Ramsey Electronics DN1 User's Manual
Contents
1. 16 Troubleshooting 21 Ramsey kit warranty 23 RAMSEY ELECTRONICS INC Fishers Station Drive 590 N 7 Victor New York 14564 Phone 585 924 4560 Fax 585 924 4555 www ramseykits com INTRODUCTION With today s ever changing technologies more appliances depend on battery power to enable their use While this gives us greater freedom it is often at the high cost of purchasing portable energy or batteries to run our portable electronic gismos Consider the cost of energy from our local electric company about 8 for a KW hour or about 450 000 joules of energy for a penny On the other hand that 500 mA H NiCad that you just purchased for about 1 75 can only supply 2250 joules of energy that s about 13 joules for 1 cent So it s fairly easy to see that energy costs about 35 000 times more when it s in a battery Nobody likes the idea of throwing all those batteries into a landfill That s the reason for the recent emphasis on using green rechargeable cells If a set of NiCad cells lasts you for a few months they can save the equivalent volume of themselves many tens or hundred times in the trash This is not only good for the environment it s also great for the wallet Nicad rechargeable batteries have been around for years but there are a few real disadvantages in their use They usually require a long time sixteen hours to recharge This2. dgaaaaaacu AA o o o AD OD 3 3 1 DN1 PARTS LIST RESISTORS 270 ohm red violet brown R12 5 ohm Watt green black silver R26 27 10 ohm brown black black R 2 10 22 470 ohm yellow violet brown R3 7 1K ohm brown black red R1 5 9 25 10K ohm brown black orange R11 20 10K ohm 196 brown black black red R16 17 8K ohm 196 brown violet grey red R14 47K ohm resistors yellow violet orange R4 6 8 13 15 17 18 19 21 23 24 CAPACITORS 1uF electrolytic capacitors C1 C3 C3A 10 uF electrolytic capacitors C2 5 6 INDUCTORS Axial lead inductor enameled wire wound on ferrite core L1 SEMICONDUCTORS AND INTEGRATED CIRCUITS 1N4148 diodes glass case with black band D2 4 7 1N4002 diode epoxy case marked 1N4002 D5 6 1N4937 fast recovery diode epoxy case marked 1N4937 D1 Light Emitting Diode LED D3 NPN small signal transistor 2N3904 or equivalent Q2 NPN power type marked TIP31C Q3 Power FET marked 7035 Q1 781 05 voltage regulator marked 78L05 VR1 BQ2003 16 pin IC U1 MISCELLANEOUS PARTS AND HARDWARE 2 5mm power jack J3 10 position DIP switch S1 DPDT pushbutton switch S2 3 DN1 printed circuit board TO 220 heatsink HS1 314 40 screws and nuts Insulated jumper wire 6 piece of two
3. Min C 2 H No Connection 180 C G J 90 2C No Connection J 45 4C H J 23 DN1 e 17 SETTING UP THE SWITCHES You ll need to configure the row of DIP switches for your battery pack now Since the minimum number of cells is at least one the conditioner is already set up for a single battery to begin with Switch No 10 is reserved for the discharging current setup When it is closed the Doctor is in low current discharge mode or about 140 mA drain from your batteries When Switch No 10 is opened the discharging current is increased to 280 mA or the high current discharge Switches 1 9 should be set for the number of cells in the pack minus one remember Dr NiCad is set up for one cell to start meaning that the first resistor in the network is always in the circuit R24 Control Switches Switch S witch Down O CX ON T Set to d Hiah Low 2 of Cells to Charge Discharge minus one Rate ONIS EUH i e 4 Cell Pack Switches 1 2 and 3 Up or ON TESTING YOUR DOCTOR NiCad BATTERY CONDITIONER CHARGER Well here it is the moment of truth Although you re probably anxious to get charging now is the best time to double check your work It is far better to discover a solder bridge misplaced component or incorrectly set switch now before the circuit is energized than risk permanent component damage from being too hasty Review your configuration setups also DN1 CHARGE STATUS LED INDICA
4. that your batteries will not be charged for too long Here s an example of how to determine the correct setup We have a battery pack consisting of 4 AA type cells The pack is marked as having 500mA hr cells with a quick charge rate of 1 Amp With a charging rate of 1 Amp the cell is storing charge at a rate of twice the capacity or 2 C The battery an ideal situation will acquire a full charge in one half hours time or mathematically speaking 1 5Hr 5A Hr or 500mA Hr Notice the Safety Time Out Jumpering Chart page 17 that for a charge rate of 2C the time out will be 45 minutes DN1e 6 Fill in the chart with the ratings imprinted on your batteries This should help you to determine the proper jumper settings Battery Type Number of Charge Charge Time Out Cells Capacity As Current Setting Hr mA Min DN1 FINAL ASSEMBLY INSTRUCTIONS Use scrap resistor leads to form the proper jumper wires to configure your conditioner Use the parts diagram to identify the proper holes for the jumper gif wires Charging Jumpers Current Used 250 mA A C B D 500 mA C D 1A A F C D B E CHARGING CURRENT SETUP SAFETY TIME OUT CONFIGURATION SETUP Setting the charge current too high can cause the cell to explode Consult the battery manufacturers specifications for proper charge current specifications Charge Jumper Jumper Charging Rate TM to 2 to Time
5. trickle charge arrangement is quite common because it is much cheaper for the original product manufacturer to produce the entire battery charger is typically a couple of rectifier diodes and a current limiting resistor and works well given the draw back of a long charge time Another disadvantage to the plug in wall transformer charger is that the charging cutoff action is regulated by the heat produced by the cells chemical reaction when recharging If you ve ever opened up a rechargeable pack you have probably seen the thermal shutoff mystery part connected and mechanically touching one cell of the battery pack While this will help if you leave your appliance charging for several days notice that it is sampling only one cell in the pack and assuming that the rest of the batteries are behaving in the the same manner Also since the ambient temperature can change i e recharging your cordless drill in the cool garage or basement or your two way radio on the hot seat in the car this heat sensing approach can vary considerably from undercharging your pack to overcharging until you cook the electrolyte solution right out of the battery Often times we cannot wait for the full recommended charging time or do not use the batteries until they re completely dead When this is repeated the uncared for battery or pack can seem to run out rather quickly This effect is caused by not completely discharging the cell before it
6. you ll still need a couple to set up your kit for its final operation DOCTOR NiCad BATTERY CONDITIONER SETUP Its time to configure your Doctor NiCad for your individual application We ll discuss a little theory first to more clearly understand the proper settings e NiCad batteries have a capacity rating or C value associated with them This value is usually defined in an Ampere Hour rating Typically the larger the battery cell the larger the Amp Hr rating e The quality of the NiCad is proportional to the charging rate of the battery That s why you have seen the exact same looking batteries i e same size shape and weight while one is called a fast charge cell and may cost twice as much Many portable motor driven devices like portable drills have higher capacity batteries for longer life The higher the quality of the cell the faster one can charge it as high as a rate of 4 times the capacity 4C of the cell Be aware however that trying to fast charge a cell not intended for this type of charge can cause the cell to build up internal gasses too quickly and explode regardless of the complexity of the charger If you cannot determine the proper charging rate for your cell the rate of C 2 is recommended e Once the charging rate is determined you can easily calculate the safety time out required for worry free operation This time is roughly 17 times the charge capacity of the cells This time out feature ensures
7. Negative Slope order Terminal Voltage Vs Time for a NiCad Cell VOLTAGE Enter the Benchmarq BQ2003 NiCad battery charger IC This cell monitoring charging IC performs all of the previously mentioned functions and then some This smart IC is the doctor in our NiCad recharging unit DN1 gt 5 We designed our kit to change quickly and easily adapt to a variety of cell or battery pack types for anything from video camcorders to cordless phones You can configure it for the number of batteries in your pack discharge and charging rate We ll discuss this later as we re assembling these sections of the circuit DN1 CIRCUIT DESCRIPTION Before we get into the technical jargon let s take a walk around the BQ2003 Integrated Circuit We ll start with some definitions of the abbreviations written on the chip in the schematic diagram Benchmark BQ2003 pin designations Pin No Abbreviation Function 1 Charge command 2 Discharge Before Charge Command 3 Enable Input 4 5 Timer Mode Outputs 7 Single Cell Voltage Input 8 Ground 9 Charging Current Sense Input 11 Maximum Cell Voltage Reference 13 Charging Status LED Output 14 Current Switching Control Output 15 Discharge Control Output 16 5 Volt input The BQ2003 charger IC handles many of the functions related to our charger Without trying to sound too much like a technical man
8. a right way and a wrong way to solder it in Diode bands electrolytic capacitor polarity transistor shapes dotted or notched ends of IC s and so forth 4 Solder all connections unless directed otherwise Use enough heat and solder flow for clean shiny completed connections Now let s get building Since you may appreciate some warm up soldering practice as well as a chance to put some landmarks on the PC board we ll first install some hardware components This will also help us to get acquainted with the up down left right orientation of the circuit board Remember that the components will be mounted on the component side of the circuit board and soldered on the solder side of the circuit board DN1e 10 DN1 PARTS FINDER DIAGRAM 0 3 Electronics REV 1 1 1 1984 abun DN1 e 11 Identify and install DPDT switch 52 Be sure to push the switches flat 1 to the circuit board Solder all six connections CJ 2 Install the other DPDT toggle power switch S3 Once again be sure to push the component flush to the circuit board before soldering We ll start our learn as you build instructions with the power supply section of the circuit CJ 3 Install the 2 5 mm power connector in the J3 position 4 Install D6 a 1N4002 type diode Notice that one end of this component is marked with a band Diodes are polarized that is like a battery they have a
9. of charging be sure to reconfigure the switches for the proper voltage setting This method is only to be used as a last resort to save a battery pack TROUBLESHOOTING INSTRUCTIONS While we had hoped that it wouldn t come to this if you are having trouble with your charger here are a few suggestions By far the most common source of problems is due to misplaced parts or poor solder connections It s always best to take a break before searching for bad connections A good way of checking component placement is to double check the assembly steps going backwards from the last steps to the the first Bright lighting and a magnifying aid can be helpful in identifying soldering problems We ve all made silly mistakes and never been able to see them ourselves so have a friend check your work as well DN1 gt 1 Use methodical logical troubleshooting technique Most problems can be solved using common sense volt ohm meter and a clear head are usually all that are needed to correct any problem Please understand that it is nearly impossible to troubleshoot by phone any specific questions should be documented and sent to us by mail The Benchmarq IC has been double checked to its ensure reliability and probably isn t the problem if your kit doesn t run COMMON QUESTIONS Q When charge my battery pack the discharge and charge cycles are short and the battery doesn t seem to have the capacity it should have A A battery is
10. shown in the parts diagram Pin 1 is located directly below the notch when the IC is positioned so that the notch is to the left If you prefer to use an IC Socket you may install one if you wish Be aware however that our techs find more repair problems due to sockets than due to chips burned out from overheating with a soldering iron Be extra careful not to bridge the printed circuit traces together 25a On the bottom side of the board install a short piece of insulated wire between pins 1 and 8 of U1 Be sure to select the right pins 26 Install R5 1K ohm brown black red 27 Install transistor the NPN power type When ONSE Heat Sink installing be sure to form the 14 a leads as shown to allow an DT easy fit Usually it is easier to mechanically mount the component with its heatsink and then solder the connections Install the screw through the heat sink and the component Tighten the nut securely 28 Install D2 134148 type diode glass case with dark band Be sure to orient the banded end as shown in the parts diagram 29 Install D4 1N4148 diode Watch that polarity See the parts diagram for proper placement 30 Install R22 10 ohm brown black black 31 Install R10 also 10 ohm brown black black 32 Install D7 1N4148 diode glass case with dark band Be sure to observe the correct polarity 7 vy You ve just completed the constant curre
11. that if you turn the input voltage too high that the higher currents created cause the large inductor in the Switching supply to saturate magnetically and lose its inductive properties Try reducing the input voltage to 12 14VDC as this took care of our fast charge problem DN1e 22 The Ramsey Kit Warranty Please read carefully BEFORE calling or writing in about your kit Most problems can be solved without contacting the factory Notice that this is not a fine print warranty We want you to understand your rights and ours too All Ramsey kits will work if assembled properly The very fact that your kit includes this new manual is your assurance that a team of knowledgeable people have field tested several copies of this kit straight from the Ramsey Inventory If you need help please read through your manual carefully all information required to properly build and test your kit is contained within the pages 1 DEFECTIVE PARTS It s always easy to blame a part for a problem in your kit Before you conclude that a part may be bad thoroughly check your work Today s semiconductors and passive components have reached incredibly high reliability levels and it s sad to say that our human construction skills have not But on rare occasions a sour component can slip through All our kit parts carry the Ramsey Electronics Warranty that they are free from defects for a full ninety 90 days from the date of purchase Defective parts will be re
12. 1 2 6 cells It can also be quite frustrating to connect the charger to these oddball type packs An inexpensive design idea is to fabricate your own holder with assorted bits of wood and plastic Surely a kitbuilder like you already has a junkbox full of those priceless gems just waiting to be put to use to hold your batteries For example an old discarded relay usually contains some high current spring loaded contacts that make great connecting terminals for such packs Be absolutely sure that you have the proper polarity identified on the battery pack Most are marked with a sticker or mark in the plastic case If you can t figure out the charge capacity go to your local home electronics store Ask about replacement cells most likely the salesman will know what you need BATTERY WORKOUT To keep your NiCad cells at their peak capacity here are a few suggestions 1 Alway deep cycle your batteries Run them until they just begin to quit It is best to depress the discharge pushbutton after you initially hook up the pack to Dr NiCad 2 Even when not in use periodically top off the pack This is also DN1e 20 handled by the doctor but if you have several packs be sure to rotate them or maybe buy a few more Dr NiCad Chargers BATTERY REPAIR Many times we have older batteries or packs that don t seem to hold a charge at all but they were so expensive that we couldn t bear to toss them in the trash We
13. Dr NiCad BATTERY CONDITIONER RAPID CHARGER Dr Nicad is your best for nicad batteries Ramsey Electronics Model No DN1 Stop shelling out a fortune on batteries Enjoy full performance from your NiCad batteries or battery packs with this sensational Quick charges batteries for laptop computers hand held radios and scanners cordless cellular phones camcorders RC models and more Charge many batteries in less than an hour e State of the art battery monitor IC safely watches both battery voltage and charge time while fast charging your batteries e Eliminate Memory Effect common to NiCads uses unique constant current circuitry SafetyFirst circuit has built in timers and voltage sensors that monitor the cell for safety it won t let you charge a bad cell Stop cooking and start conditioning your rechargeable batteries no more leaving the charger plugged in for days on end e Charges single cells as well as NiCad packs from 1 to 10 cells e Automatic top off charge keeps batteries at their peak power until use e Unit runs on 12 15 volts DC Convenient flashing LED indicates charging modes and eliminates guesswork RAMSEY TRANSMITTER KITS FM10A FM25B FM Stereo Transmitters FM100B Professional Quality FM Stereo Transmitter TV6 Television Transmitter AM1 AM25 AM Transmitters RAMSEY RECEIVER KITS 1 FM Broadcast Receiver AR1 Aircraft Band Receiver SR2
14. Shortwave Receiver Active Antenna SC1 Shortwave Converter RAMSEY HOBBY KITS 567 Personal Speed Radar S870 Speech Scrambler TT1 Telephone Recorder SP1 Speakerphone MD3 Microwave Motion Detector PH10 Peak hold Meter LC1 Inductance Capacitance Meter RAMSEY AMATEUR RADIO KITS DDF1 Doppler Direction Finder HR Series HF All Mode Receivers QRP Series HF CW Transmitters CW7 QRP Power Amplifiers RAMSEY MINI KITS Many other kits are available for hobby school Scouts and just plain FUN New kits are always under development Write or call for our free Ramsey catalog DOCTOR NiCad BATTERY CONDITIONER KIT INSTRUCTION MANUAL Ramsey Electronics publication No MDN1 Revision 1 1a First printing March 1994 COPYRIGHT 51994 by Ramsey Electronics Inc 590 Fishers Station Drive Victor New York 14564 All rights reserved No portion of this publication may be copied or duplicated without the written permission of Ramsey Electronics Inc Printed in the United States of America DN1e 2 Ramsey Publication No MDN1 Price 5 00 KIT ASSEMBLY AND INSTRUCTION MANUAL FOR Dr NiCad NiCad BATTERY CHARGER CONDITIONER TABLE OF CONTENTS Introduction to the DN1 4 How it works 6 Parts list dee 8 Schematic diagram 9 Parts Layout diagram 11 DN1 Assembly instructions 12 Setup configurations
15. TOR When powered up Dr NiCad s front panel LED is much more than a power DN1e 8 Charger Status Status LED ON time Status LED OFF time No Battery No Light No Light Battery Connected 1 8 sec 1 8 sec Awaiting Command Discharging 1 3 8 sec 1 8 sec Fast Charging Continuous N A Charge Complete 1 8 sec 1 8 Topping Off 1 8 sec 1 8 sec indicator By changing the ON OFF times this LED becomes a charging status indicator Use the following chart for an indication of what the doctor is telling you POWER SUPPLY CONSIDERATIONS The power supply used for the Dr NiCad can very greatly depending on how you set up your charger to work While you may be able to get away with many different types of supplies what s recommended is a regulated 12 14VDC supply capable of supplying at least 1 5 Amps of current continuously When using the doctor in the field a 12 VDC car battery works well as a power source Be sure to remember that the center pin of the input power connector J3 should be connected to the positive terminal of the supply and the outer connector is attached to the negative or terminal THROTTLE UP With all our configuring steps behind us it s time to use the doctor O 1 Connect the battery or batteries to be charged to the V red and V wires 2 Connect the power input to the circuit 3 Switch S3 to the ON position The Status LED should come up in
16. black red 41 Install R11 10K ohm brown black orange 42 Install R20 10K ohm brown black orange 43 Lastly install the provided hookup wire red to the V black to the V into the circuit board Due to numerous types of battery packs used this two wire type of hookup is as far as we go Many types of battery holders can be found quite reasonably priced at your local electronics store Please understand that it was nearly impossible for us to predict the type of pack that was to be charged with this kit O 44 Since the 52 switch that was previously installed comes from the factory as a toggle switch but our application uses a pushbutton input we ll need to make a small modification to the mechanics of the switch to suit our purpose Locate the switch guide pin on switch S2 With a small pliers gently lift the pin and rotate it so it does not remain in the toggle groove See the accompanying diagrams for help Switch Guide Pin Toggle Position Switch Guide Pin Push Button Positio DN1 e 15 CONGRATULATIONS You have just completed your DN1 NiCad battery conditioner unit Take a well deserved break now Give your eyes a rest When you return be sure to check over your work on the entire circuit board Energizing the circuit board with solder bridges or misplaced components can damage your kit Don t throw away all your scrap component leads just yet however
17. conductive wire blk red DN1 8 DN1 9 RAMSEY Learn As You Build KIT ASSEMBLY There are numerous solder connections on the DN1 printed circuit board Therefore PLEASE take us seriously when we say that good soldering is essential to the proper operation of your Doctor Nicad Use 25 soldering pencil with a clean sharp tip Use only rosin core solder intended for electronics use Use bright lighting A magnifying lamp or bench style magnifier may be helpful Do your work in stages taking breaks to check your work Carefully brush away wire cuttings so they don t lodge between solder connections We have a two fold strategy for the order of the following kit assembly steps First we install parts in physical relationship to each other so there s minimal chance of inserting wires into wrong holes Second whenever possible we install in an order that fits our Learn As You Build kit building philosophy This entails describing the circuit that you are building instead of just blindly installing components We hope that this will not only make assembly of our kits easier but help you to understand the circuit you re constructing For each part our word Install always means these steps 1 Pick the correct part value to start with 2 Insert it into the correct PC board location 3 Orient it correctly follow the PC board drawing and the written directions for all parts especially when there s
18. either the Fast Charging mode or Awaiting Command mode 4 To cycle the batteries depress pushbutton switch S2 The Status LED should display the discharging mode au Once the batteries are discharging Dr NiCad will take it from there The conditioner will first discharge the cells to about 9 1 0 Volts per cell and DN1 e 19 begin the Fast Charging mode The Benchmark IC will constantly monitor the pack and turn off the fast charge when the cells are charged just to full capacity Once this is accomplished it will periodically top off the cells with a high current burst and allow a slight trickle charge to flow Unfortunately about the only thing to do for this initial check out is to watch the lights blink but it is also a good time to measure the capacity of your cell Start timing the charger just when it goes into fast charge mode Knowing the charge current rate whatever you previously set it up at and the time for a full charge Amperes Hours you can get a fairly good approximation of the health capacity value of your batteries What about those mystery batteries Often times the batteries are hidden in elaborate packs designed to fit in video cameras cordless phones or RC racecars The easiest way to determine the number of cells in such a pack is to take the nameplate voltage and divide by the number 1 2 the voltage of a single cell For example a 7 2 V pack contains 7 2 gt
19. is recharged and is known as the memory effect since the battery appears to memorize the amount of energy it is called upon to produce By not completing the DN1 4 oxidation reduction or redox chemical reaction in the cell we effectively decrease the chemically active surface area inside the cell The lower this surface area the shorter the battery s life Since you don t try to recharge conventional batteries you ve never noticed this property until you started to use rechargeable NiCad batteries To keep your cells working like new and to eliminate this memory effect we ve built in an automatic discharge circuit that will properly discharge the cells before their recharging So you can see recharging a NiCad battery correctly can be a tricky business How can we charge the battery to its full potential but not too much The answer is to watch the AV or change in voltage over time As shown in the graph the battery voltage continues to rise while charging but drops slightly when the cell is completely charged By recognizing this point on the graph a charger can put just enough charge into the cell By virtue of this voltage vs time checking it is also possible to charge the battery at a much higher charging current and significantly reduce the battery charging time Once this point is reached it is best to top off the battery with a charge burst every now and then Positive Slope Full Charge OF ee Slope Zero
20. isfied you may return your unassembled kit with all the parts and instructions and proof of purchase to the factory for a full refund The return package should be packed securely Insurance is recommended Please do not cause needless delays read all information carefully DN1 e 23 DN1 Dr NiCad BATTERY CONDITIONER Quick Reference Page Guide Introduction to the DN1 4 How it 6 Parts list inp 8 Schematic diagram 9 Parts Layout diagram 11 DN1 Assembly instructions 12 Set up configurations 16 Troubleshooting 21 Ramsey kit warranty 23 REQUIRED TOOLS e Soldering Iron WLC 100 e Thin Rosin Core Solder RTS12 e Needle Nose Pliers MPP4 or 505 e Small Diagonal Cutters 504 ADDITIONAL SUGGESTED ITEMS e Helping Hands Holder for PC Board Parts HH3 e Technician s Tool Kit TK405 e Desoldering Braid 508 Price 5 00 Ramsey Publication No MDN1 Assembly and Instruction manual for RAMSEY MODEL NO DN1 Dr NiCad BATTERY CHARGER CONDITIONER KIT Gs ramsey RAMSEY ELECTRONICS INC 590 Fishers Station Drive Victor New York 14564 Phone 585 924 4560 Fax 585 924 4555 www ramseykits com TOTAL SOLDER POINTS 165 ESTIMATED ASSEMBLY TIME Beginner 5 0 hrs Intermediate 2 8 h
21. ll your frugality some people call it being cheap has finally paid off Most of these extreme memory conditions can be cycled right out of the pack Simply configure your Dr NiCad for the proper voltage install the pack and press the discharge button For best results if you are charging a cell greater than 1 5V these are made up of many 1 5V cells charge the first few times on the C 2 250 mA setting Additionally you should use the lower discharge setting also This will give the cells a chance to equalize their voltages bringing more life back to the pack Dr NiCad will run your batteries through a discharge charge cycle By continuing this process over and over the number of times depends on how bad the pack was to start with you can gradually build up your batteries capacity to full strength again This is probably the most satisfying use of your Dr NiCad charger see told you could fix If when you initially hook up these sick battery packs the front panel indicator wont let you discharge don t worry The lower current trickle charger is bringing the pack up to the correct minimum cell voltage to begin rapid charging Another method of jump starting a very old or abused pack is to initially open one additional switch in the voltage divider ladder This will make the pack voltage appear higher to the charger so the high current charge will be initiated Use caution when doing so however and after a few minutes
22. made up of 1 5V cells If these do not have equal voltages your battery capacity may be very short To correct this charge the battery on the C 2 250 mA setting and discharge it using the low current discharge setting four or five times For further information please see the section labeled BATTERY REPAIR When energize the circuit the indicator light just blinks in the awaiting command mode I press the discharge start button but nothing happens A Check the number of cells switch settings Be sure that it is set to the number of cells minus one Dr NiCad thinks that you need more cells in your pack This can also occur when the pack is severely discharged If you re sure that the DIP switch settings are correct Leave the pack connected to the charger The circuit includes a low current trickle charger designed to bring the cell up to an acceptable level before fast charging The doctor will then begin its fast charge sequence all on its own Q The unit was working before but now when turn it on the indicator light stay off A Again check the number of cell switch settings Dr NiCad sees more batteries connected than what you have called out with the switches Q The batteries don t seem to take a full charge that is the time required at the charging rate that l ve selected seems way too short can hear the switching supply whistle coming from the circuit board A This happened to us too Turns out
23. n in the parts diagram 9 Install C2 10 uF electrolytic Observe the correct polarity If installed incorrectly this component can heat up and even explode That wasn t so bad now was it You have just completed the power section of your DN1 Take a moment now to recheck your solder connections and touch up any less than perfect connections Have a second look at the component polarities in this section as the majority of these components have a and orientation 3 10 Install 470 ohm yellow violet brown DN1e 12 o 11 Install R1 1K ohm brown black red 11 Install Q1 the power FET transistor marked 7035 Form the leads as shown prior to installation Bolt the Power FET regulator to the circuit Tab j board 12 Install L1 the large axial leaded wire wound vY inductor Solder Connections 13 Install D1 1N4937 fast recovery diode Observe the correct polarity Note also that this is another stand up diode so form the leads as before for a proper fit 14 Identify Q2 a 2N3904 NPN transistor When installing Q2 observe correct placement of the flat side Press the transistor snugly into the PC board so that only a minimum amount of wire lead is exposed above the board In soldering do not be afraid of using enough heat to make a good solid connection 15 Install R9 1K ohm brown black red That s it for the switching high current
24. nt battery discharging portion of the circuit This section when initiated will discharge the battery at a constant rate until the Benchmarq IC senses that the cell voltage is low enough for a complete recharge Recheck your work for any solder bridges especially on the IC or incomplete solder connections A bright light and a magnifying lens can be helpful for this We ll continue building the final section of the Doctor NiCad circuit the voltage sense inputs and voltage divider Notice the resistor ladder in the schematic diagram By configuring the switches to the proper number of cells in the pack we divide the battery input voltage by the number of cells DN1e 14 present giving us an accurate representation of one cell contained the pack 33 Install R21 47K ohm yellow violet orange O 34 Install DIP switch S1 D ual I nline P ackage Make sure that the switchable contacts face toward the outside of the circuit board allowing for easy changing of number of cells to charge 35 Install 47K ohm resistors R19 R18 R17 R15 R13 R8 R6 and R4 yellow violet orange Pay extra attention in soldering not to create any solder bridges between circuit traces 36 Install R24 47K ohm yellow violet orange 37 Install R27 and R26 both 5 ohm watt green black silver 38 Install R2 10 ohm brown black black 39 Install R23 also 47K ohm yellow violet orange 40 Install R25 1K ohm brown
25. placed promptly at our expense If you suspect any part to be defective please mail it to our factory for testing and replacement Please send only the defective part s not the entire kit The part s MUST be returned to us in suitable condition for testing Please be aware that testing can usually determine if the part was truly defective or damaged by assembly or usage Don t be afraid of telling us that you blew it we re all human and in most cases replacement parts are very reasonably priced 2 MISSING PARTS Before assuming a part value is incorrect check the parts listing carefully to see if it is a critical value such as a specific coil or IC or whether a RANGE of values is suitable such as 100 to 500 uF Often times common sense will solve a mysterious missing part problem If you re missing five 10K ohm resistors and received five extra 1K resistors you can pretty much be assured that the 1K ohm resistors are actually the missing 10 parts Hum m m guess the band really does look orange Ramsey Electronics project kits are packed with pride in the USA If you believe we packed an incorrect part or omitted a part clearly indicated in your assembly manual as supplied with the basic kit by Ramsey please write or call us with information on the part you need and proof of kit purchase 3 FACTORY REPAIR OF ASSEMBLED KITS To qualify for Ramsey Electronics factory repair kits MUST 1 NOT be assembled with acid co
26. positive and negative side Be sure to follow the parts diagram carefully and orient the banded end as shown Note also that this component will stand up in place Form the component leads as shown before installing the part 5 In the same manner install diode D5 134002 type Be sure to orient it correctly See the parts diagram for correct placement Diodes D5 and D6 act as circuit protection If the power is hooked up incorrectly D6 acts as an open circuit to prevent damage to the voltage regulator and the charger IC Diode D5 prevents the battery pack under charge from powering the unit if the input power is accidentally removed O 6 Install C5 10 uF electrolytic capacitor Electrolytic capacitors are polarized with a and a lead and must be installed in the correct orientation Ordinarily only the negative side is marked on the capacitor body with a dark band and the sign clearly shown while PC boards will usually show the hole location Use care to ensure proper polarity See the parts diagram for proper placement 7 Install 10 uF electrolytic capacitor Watch the orientation See the parts diagram for proper placement Identify VR1 the 781 05 voltage regulator marked 7805 This device 8 produces a stable 5 volt reference for the circuit Notice that this component has a flat side with the writing imprinted on it Be sure to place the part as show
27. re solder or flux 2 NOT be modified in any manner 3 BE returned in fully assembled form not partially assembled 4 BE accompanied by the proper repair fee No repair will be undertaken until we have received the MINIMUM repair fee 1 2 hour labor of 25 00 or authorization to charge it to your credit card account 5 INCLUDE a description of the problem and legible return address DO NOT send a separate letter include all correspondence with the unit Please do not include your own hardware such as non Ramsey cabinets knobs cables external battery packs and the like Ramsey Electronics Inc reserves the right to refuse repair on ANY item in which we find excessive problems or damage due to construction methods To assist customers in such situations Ramsey Electronics Inc reserves the right to solve their needs on a case by case basis The repair is 50 00 per hour regardless of the cost of the kit Please understand that our technicians are not volunteers and that set up testing diagnosis repair and repacking and paperwork can take nearly an hour of paid employee time on even a simple kit Of course if we find that a part was defective in manufacture there will be no charge to repair your kit But please realize that our technicians know the difference between a defective part and parts burned out or damaged through improper use or assembly 4 REFUNDS You are given ten 10 days to examine our products If you are not sat
28. red and delivered to the battery cells being charged This is what provides us with the high current to quickly charge the cell but does not dissipate power in the FET or NPN transistor making the switched power much more efficient than a conventional pass transistor type of supply Another contributing factor to the charging circuit is the charge rate setup which is configured using resistors R26 and 27 as well as test points A F Transistor Q3 is the integral part of our constant current discharging circuit When the chip sees a positive going pulse at the DCMD pin it initiates the DIS discharge output With switch 51 10 closed diodes D2 D4 are forward biased causing 1 4VDC to be present at the base of Q3 With 1 4 V at the base there is 7 VDC at the emitter a diode drop in potential lost through the transistor With the emitter at 7 VDC the current through resistors R10 and R22 is about 140 mA regardless of the cell voltages If Switch 51 10 is opened the potential increases to 1 4 VDC increasing the current to 280 mA This will continue to discharge the batteries until they reach a potential of about 9 volts per cell The Benchmarq chip then initiates its own charging sequence A few final points concerning the TM1 and TM2 time out which are configured using points G J They are dependant on the charge capacity or C of the pack We ll discuss this in more detail when it comes time to configure these jumpers DN1 7
29. rs Advanced 2 1 hrs
30. supply This part of the circuit provides the muscle to charge the batteries o nanaonan 16 Install LED D3 This component is polarized and must be oriented correctly Examine the LED and notice how one lead is longer than the other Most diodes also have a flat mold in one side of the component body This flat side is on the same side as the shorter leg When properly installed the flat side should face towards S2 Leave the diode leads as long as possible because this component will mount to the front panel as a charging status indicator Leave these leads b as long as possible PC Board 17 Using scrap component lead form a jumper wire and install it in the JMP2 position A jumper acts as an electronic bridge to carry power and signal over the traces run underneath 18 Form and install another jumper JMP1 19 Install R7 470 ohm yellow violet brown 20 Install R12 270 ohm red violet brown 21 Install R14 17 8K ohm 196 brown violet grey red 22 Install R16 10K ohm 196 brown black black red DN1 e 13 Od 23 Select two of the 1uF electrolytic capacitors and solder the ground leads together Install them as C3 Bend the ground leads away from 01 24 Install C1 the remaining 1uF capacitor The positive side should be facing R5 25 Install the Benchmark BQ2003 IC Notice that one end of the chip is marked with a dot notch or band Be sure to orient this end as
31. ual or data book here s a closer look at some of the accompanying circuitry Have a glance at the schematic diagram and follow along DN1 6 Since we want the voltage appearing at the IC to be equivalent to one cell we first must divide the cell voltage by the number of cells in the pack The ladder resistors R2 R24 form an effective voltage divider circuit so that the BAT pin 7 voltage will be about 1 25 V per cell The switch can increase or decrease the BAT voltage by adding or subtracting rungs from the voltage divider ladder Another divider network consists of resistors R14 and R16 This voltage sets up the MCV voltage for the BQ2003 IC This should measure 1 8 V when in operation Seeing how you ll want to charge your batteries quickly you need a high charging current power supply to back you up Transistors Q2 Q1 and components D1 and L1 form the high current portion of our switched mode regulator circuit When the MOD output goes high transistor Q2 is turned on like a switch This current then flows into the battery Resistor R29 and or R27 is in series with the current flow and the voltage drop across it is sensed by IC pin 9 the sense pin When the sense pin reaches its trigger point the transistor is abruptly turned off When this occurs the magnetic field around the coil quickly collapses and causes a reverse voltage spike which is routed through the catch diode D1 This energy is recove
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