Looking for some technical in put. Have a GMC/Homelite 1Kva generator with a faulty AVR module Have replaced the blown IRFS640 Mosfet & checked the 2N5551 transistor which is ok. It still wont work so I cracked open the resin from the PCB & tried to draw thecircuit to the best of my ability, some resistors broke so cant measure them. Surely there is a retired Electronics Engineer here who can tell me if my circuit is corect & likely to work, & what the value might be of the resistors which are unmarked, or any other things that might be wrong. I am keen to rebuild a regulator as there is only about 20 parts in it, & cant see why they are worth about $200. Have included voltages to the rotor under various loads by forcing the generator to work, by rectifying the 90V ac & feeding through a 40Watt resistor to the rotor. At least this proved the generator works & the AVR is faulty. Help!!! Daryl
DeBe said
10:42 AM Sep 22, 2010
Just noticed C1 should be betwean R1 & R5. Daryl
DeBe said
04:53 PM Sep 23, 2010
Sucsess at last have posted the corect & fully working circuit for the AVR unit. The easies & cheapest way was to remove all the parts & start again with new parts, only parts re used was the large cap & trim pot. If to was to replace all 24 components the cost woul still only be $14. So realy happy with the results, The C1 capacitor was also faulty & was only 16V rated so was replaced with a 35V unit as there is 18V across it. Daryl
DeBe said
08:09 PM Sep 25, 2010
The final result, the AVR unit is now mounted in the black box under the fuel tank & bolted to the front panel as it wont mount inside the end on the generator now.
Cupie said
03:05 PM Sep 26, 2010
Well done ....
Just noticed this post & was about to mail it to an electronics guru mate.
Won't have to worry him now. Though I'm certain he would have redesigned the circuit & added a range of bells & whistles. That is if it ever got to the top of his list or grabbed his creative attention.
BobnBev said
08:41 AM Sep 29, 2010
Good on you for sticking with it most people would dump it for scrap and get a new one . I have 2 of them in the shed .. both go .. The way to go..fix it its more fun..
redtails said
09:52 AM Oct 3, 2010
yes.... well done on fixing this problem, and great to know so many others are keen to help.
BobnBev said
05:24 PM Oct 5, 2010
Redtails , That car you have there needs a little bit of paint and it would be a goer.. It also needs some air in the left hand tyre.. Other than that it looks good..I see the air con is working well.........
Just noticed this post & was about to mail it to an electronics guru mate.
Won't have to worry him now. Though I'm certain he would have redesigned the circuit & added a range of bells & whistles. That is if it ever got to the top of his list or grabbed his creative attention.