therm is tor pic pulser kit instructions

12V Thermistor PIC Pulser of 5 www.courtiestown.co.uk

THERMISTOR PIC PULSER KIT INSTRUCTIONS

Parts List

R1, R10 680R (BlGyBr) R2, R5 1k (BrBR) R3, R6 3k9 (OWR) R4, R7 2k (RBBBrBr) R8, R11, R12 1k8 (BrGyR) R9 39k (OWO) R13 4k7 (YPO) VR1 1k trimmer TR1 47k thermistor C1, C2, C6, C7 0.01 or 0.1uF (not critical) C3, C5 100uF C4 2200uF or greater L1 220uH (marked 221L) L2 1000uH (marked 102L) IC1 PIC12F683 + 8-pin DIL socket Q1 IRF9640 Q2, Q3 2N3904 Q4 2N3906 D1 6V2 zener (marked 6V2 or 1N5234B) D2 5V1 zener (marked 5V1 or 1N5231B) D3 BYW29-200/ BYV29-500 or similar D4 BYV29F-200 or equivalent (plastic coated to help prevent shorting) D5 15V zener LED1 Green LED LED2 Red LED Heatsink 1 off (for fitting to D3) Fuseholder 1 off Fuse 2A 20 x 5mm QB fuse 2 off 3mm bolt 1 off 3mm nut 1 off 4mm bolt 2 off 4mm nut 4 off 4mm washer 4 off PCB 1 off


Schematic


Assembly Instructions

1. Check all component parts as listed above are present. I’m assuming you have a

reasonable level of electronic competence in having purchased this kit, please make sure you correctly identify each part.

2. Carefully remove the PIC from the 8-pin DIL socket it was shipped in and put it

somewhere safe. 3. You will need to drill out the two 3.3mm holes marked +ve and –ve to 4mm and insert

one of the 4mm brass bolts into each and secure tightly with a single nut. You then need to solder the brass head to the PCB – this will take a fair amount of heat

but the solder will flow eventually. Allow the board to cool down on completion!! The solder ensures a good solid electrical connection.

4. Then attach the two washers and remaining nut to each of the bolts – makes sure you

don’t lose them. 5. Components can then be inserted in size order as is common with most electronic kits,

however leave L2 out for now and do not insert the PIC yet either. 6. Insert two wire links across J1 and J3. 7. D3 should be loosely attached to its heatsink and then soldered to the board. The bolts

should ideally be shortened but this is not strictly necessary. The bolt can be tightened once the components are soldered to the board. It would be prudent to use some heatsink paste to aid heat transmission.

8. My personal preference as regards fitting the thermistor is to have it stuck up in the air

rather than close mounted to the PCB, this allows it to better absorb the ambient heat. It may be prudent to sleeve the legs in this case.

9. Use the thickest multi-strand wire you can to connect the fuseholder (this connected

across J2) and keep the wire length as short as practicable (I’m assuming you are going to be mounting this device in a case!!). The PCB holes are 2.1mm diameter to aid this.

10. The trimmer potentiometer should be adjusted to the maximum clockwise position for

start-up. 11. Thoroughly check the underside of the board prior to connecting up to carry out any

testing. 12. I do not know what level of equipment you will have, I’m assuming a minimum of a DMM

and an oscilloscope would be a bonus.


13. With L2 not soldered to the PCB and the PIC out connect the device to a 12V battery. For testing purposes any old bit of wire will do but I would recommend using at least 12

or 10AWG multi-strand cable with soldered ring terminal connections for the device when functioning with batteries.

You should see the red LED light up and then slowly go dim, this is C4 charging up and is nothing to worry about.

13. Check you have circa 5.1V across D2 and 6.2V across D1. Then check you have 5.1V at

pin 1 of the IC socket and 0V at pin 8. This shows voltage is flowing where it should in the circuit.

14. Assuming this bit is OK then if you have an oscilloscope connect the probe to the gate

(and the earth to the negative supply) of Q1 (or use the end of R9 nearest Q1 as it is easier to access) and with a jumper wire carefully make a connection from pin 1 of the IC socket to pin 2 of the IC socket and you should see the MOSFET go on. You will also see this with a DMM if you don’t have a scope. You should see the battery voltage drop to around 0.7V as the MOSFET switches.

This bit shows the MOSFET drive circuitry is OK. 15. Time to get brave now. Solder L2 in to the PCB and then insert the PIC and ensure the

trimmer potentiometer is turned fully clockwise. 16. Re-connect the power. After about 2 seconds the green LED should illuminate and then

after a further 3 seconds the red should also illuminate. So far so good – don’t be alarmed that you can’t hear anything at this point. If equipped with an oscilloscope you could of course keep the probe attached to the gate

of Q1/ end of R9 and this will give a clear indication of what is going on. Very carefully turn the trimmer anti-clockwise and the device should ‘burst into life’ very

audibly. There is no best fixed position for the trimmer, you will need to adjust it then leave it

running for 15-20 minutes for the heat to even out in all components. The Mk1 finger tip is a very good indication of heat, obviously you don’t want to be

cooking any one component but some heat indicates work is being done. 17. To test the thermistor overheat you’ll need a heat shrink gun (or a hair drier), either, used

carefully, will cause the device to cut-out and the red LED to flash. Once the thermistor has cooled again the device will just resume pulsing.


SIMPLE PIC PULSER / DESULFATOR INSTRUCTIONS

DO NOT CONNECT THE PULSER DIRECTLY TO THE BATTERY CHARGER – CONNECT IT TO THE BATTERY & THEN CONNECT THE CHARGER TO THE BATTERY. MAKE SURE THE BATTERY CHARGER

IS UNPLUGGED FROM THE MAINS SUPPLY BEFORE CONNECTING/ DISCONNECTING. DO NOT CHARGE BATTERIES ABOVE 15V AS THE PULSER IS NOT DESIGNED FOR VOLTAGES ABOVE THS.

1. The start-up sequence for the PIC desulphator is that initially no LED’s will light then after a short period the GREEN LED will illuminate and then after a further 3-4seconds the RED LED will illuminate and the unit will emit a circa 1KHz buzzing tone.

2. Please ensure that any battery charging activities are carried out in a reasonably well ventilated

environment. This is particularly relevant here as you will both hear and see sparks generated as you connect this device. This is perfectly normal, but possibly ‘alarming’ to the first time user.

3. Also ensure that as a minimum you wear suitable eye protection when working with and around charging

batteries 4. The battery to be recovered must, ideally, measure at least 10.5V ‘open circuit’. Any less than this and the

cause of the battery’s deterioration may well be more than sulphation and this device is unlikely to function as intended i.e. recover a sulphated battery.

5. Ensure that the electrolyte levels are adequate prior to starting, these should be checked regularly whilst

the device is in use. It may seem obvious but don’t do this with the pulser connected, they don’t like water.

Maintaining the electrolyte levels is critical when using a desulphator, the units generate sparks and if the battery plates become exposed these sparks will ignite the hydrogen gas present and potentially, cause the battery to explode.

6. The device should be used in conjunction with a simple trickle battery charger. 7. The device can be left connected whilst the trickle charger is connected/disconnected from the battery. I

re-iterate, do not leave the desulfator connected solely to the battery charger. 8. Having said this, the device can be used on its own, i.e. without a charger until the battery voltage drops to

12.0V (10.5V if a deep cycle type), i.e. trickle charge the battery in conjunction with the pulser until a peak is reached and then disconnect the charger and let the pulser ‘pull’ the battery voltage down. Depending on the state of the battery this could be several days.

9. If you have a voltmeter, the simplest indication of the battery improving will be the maximum voltage

achieved after charging each time. This should rise noticeably during the first week and then reduce over time.

The next best reliable indicator is putting a load on it, i.e. put it in a vehicle and try starting it – probably the simplest ‘load test’ around.

10. I cannot emphasise enough the importance of ensuring the voltage level doesn’t drop below 12.0V (10.5V for s deep cycle) at any time. It is almost certain irreversible battery damage will result.

11. Ready built desulphators have been bench tested prior to despatch. 12. These devices are supplied with integral reverse polarity and thermal overheat protection. If you connect the device to the battery the wrong way around the externally mounted fuse will blow (a 5 x 20mm 2A quick-blow type). I would suggest you get a stock of these in as we have all made the mistake of connecting these devices the wrong way round; the advantage now is that you only blow the fuse and not the whole device!! The thermal overheat operates automatically when the case internal temperature reaches 60

oC. The device will

cut-out automatically and the GREEN LED will flash indicating the cause of the ‘failure’ to be overheating. Once the unit has cooled below 60

oC it will resume operation automatically.

If your unit does this frequently please let me know.

therm is tor pic pulser kit instructions

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