Hi guys I need some help.

I have read all the posts on the transistors to repair a PGM3 and have searched the parts numbers but can't find them with the "Z" on the end, I can find them without the "Z" is this the same?
Can anyone confirm the part numbers and where they can be purchased.
Also as my power valves are not working at all how do I first test the power valve servo motor to make sure it cycles and that this is not the problem?
The valves are not tight and can be moved in both directions from hi to low.

Any direction would be much appreciated.

Howzit ,
good luck with the pgm repair . I can have a look for a spare powervalve motor for you to compare . In my experiances it has been the pgm that was faulty .

Cheers , Neal

Neal wrote:Howzit ,
good luck with the pgm repair . I can have a look for a spare powervalve motor for you to compare . In my experiances it has been the pgm that was faulty .

Cheers , Neal

Thanks Neal, I work in Durban but live in JHB, do you have an MC21 with a working PGM3 if possible could I bring my PGM3 down to test???

Some transistors are regularly advertised on Yahoo.

I'm currently looking into them with another member on here to see if they work and are available. Still early days yet, but it looks as though they can be obtained in bulk through industry contacts. We just have to get a sample first.

Howzit , bring your pgm and we can check it with a known running bike . I am using a pgmii .

I might have a blown pgmiii if anyone wants to disect it .

Middo wrote:Some transistors are regularly advertised on Yahoo.

I'm currently looking into them with another member on here to see if they work and are available. Still early days yet, but it looks as though they can be obtained in bulk through industry contacts. We just have to get a sample first.

It looks like they are available I have found a website with both types but they do not have the -Z on the end. I have asked a friend in HK if he can help. Here is the weblink.

http://translate.googleusercontent.com/translate_c?hl=el&ie=UTF8&sl=ja&tl=en&u=http://www.kashinoki.co.jp/page010.shtml&rurl=www.google.com&usg=ALkJrhjeQlamZs67ISBEJ7EUPA3eZIvqRA

Good idea.
While you are at it, couldn't you find out how much current is used by the Valve motor normally and when blocked and design a protection circuit, so the transistors won't burn out again.

Do you have any tips on how to remove the rubber compound ?
_________________
Poul
"If Life Gets Boring, Risk It!"
MC21SE, KISS box
MC21SP, HRC box, racing loom

pbekkerh wrote:Good idea.
While you are at it, couldn't you find out how much current is used by the Valve motor normally and when blocked and design a protection circuit, so the transistors won't burn out again.

Do you have any tips on how to remove the rubber compound ?

When I get it working I'll measure the working amps and stalled amps to see what it is but I have a feeling it is only small. trying to stop them from burning out will be near impossible but you could put an L.E.D on the instrument panel with a circuit to switch when the servo is pulling more than normal amps, this would then prompt to clean the power valves. Best I can think of but I'm not an electronic's fundy!
To remove the rubber compound just takes time with tweezers and a sergical knife being very careful not to damage the board from what I understand, will let you know how it goes.

A protection system is easy, it's called a fuse! Better still a circuit breaker, so when the thing draws too much current the circuit breaker pops and you know it's time to de-coke...

I thought about this a lot a while back, but never got round to doing something about it.
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Why not just regularly clean the RC Valves and adjust the cables?
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Andy.
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I've replaced the transistors on a couple of boxes and at least one of them has gone pop again after working for some time.

It's a messy and seriously time consuming job to remove the potting to get to the components, but if you can be bothered then it can be done.

As for finding these parts. I have one set left, but in typical Thai fashion, the shop where I got them now says that they don't exist. Erm, I got them from you Sir.......No you didn't......Well this packet just happens to have your shop name on it.........

A chum of mine fitted an inline fuse, as Dave suggests. Worked fine.

Another option is to run a programmable servo controller. I have one and it basically monitors rpm (and the TPS if you want) and controls the servo by reading the output of the potentiometer inside the servo housing. Just like the PGM does. Then you can play with RC valve timing all day.

So, can we look forward to a Tyga PGM replacement for the Honda PGMIII? All the OEM ones will die someday, and it would be nice to see an alternastive while there is still a sufficient market for them.

Still playing.

My 300 runs a programmable unit. Ignition timing is adjustable vs rpm and TPS. RC valve timing is adjustable vs rpm and TPS.

Other goodies; various rpm/tps switches, shifter light & more.

Dave Ett wrote:A protection system is easy, it's called a fuse! Better still a circuit breaker, so when the thing draws too much current the circuit breaker pops and you know it's time to de-coke...
.......

In most cases a simple fuse is not enough to protect semiconductors, as a fuse is very slow, depending on how high the current is, and very unprecise and a semiconductor burns out very fast.
At double the nominal current it can be many seconds up to minutes before it breaks. (10% over = 100hours! 200% 0,15-20seconds)
There are special semiconductor fuses, that are faster, but normally you would build either an electronic circuit to blow the fuse or to clamp the voltage/current

http://www.littelfuse.com/data/en/Data_Sheets/FKS80V.pdf
_________________
Poul
"If Life Gets Boring, Risk It!"
MC21SE, KISS box
MC21SP, HRC box, racing loom

I've done a little research.

the current when the valve servo hit´s the stop is 780mA and the FET transistor is rated at 5A, so it looks like the transistors are burnt because of a sustained high current which, over time, heats them up so they burn.

If this is the case, then a fuse could be usefull.

I've also tried a small bulb in series, as its very low resistance when cold, at low current, but at higher current it heats up and the resistance increases, so it acts as a current limiter and you get a bonus, as the bulb will light up when the servo is drawing excess current.
The bulb I'm using, limits the max. current to 170mA which is a factor 4. This could be enough to protect the transistors of the PGM

The resistance at low current makes the servo go a little slower but I don't know if this will be a problem when running the bike.

I still need to know the running current of the servo, also the output voltages from the PGM and the schematic of the transistor circuit if anyone has it ?
_________________
Poul
"If Life Gets Boring, Risk It!"
MC21SE, KISS box
MC21SP, HRC box, racing loom