throttle position sensor...help needed with circuit!

[Calos]

Bushwhacker is near impossible to upset - and I dont think anything you said would have done.

Think he's just jealous cos you have access to such wonderful geekery!

Which reminds me - you being a musician who works in an electronics parts store. You dont know where I could get a diagram of the PSU for a Behringer Eurodesk SL2442FX Pro do you - or alternatively know where I can get a replacement PSU (other than from Behringer). It's a chinese switch mode jobbie, not made by Behringer.

Hum, I'd need a little more info, is it an external psu? and if so what is it rated at, volts/amps and is it ac or dc? switched mode sounds like dc, but I've some weired and wonderful stuff from DOD/digitech that was switched but ac.. oo


edit
did some google research

http://www.behringer.de/EN/downloads...P0244_S_EN.pdf

Internal, hummm not gonna have one in Maplin, but most likely RS will, "Rodger re-vamp" is a local electronics engineer, especialy with muso kit. I'll see if I can get his email and pm it to you, this would be right up his ally.

peace
cal

[Calos]

No upset caused, and I thank you for you're endorsement.



Now then, how much discount do you get??

Thank you Bushwacker, and to answer your question........ ermm this a public forum right?

oO

Not that much really

peace
cal

[Apache]

Hum, I'd need a little more info, is it an external psu? and if so what is it rated at, volts/amps and is it ac or dc? switched mode sounds like dc, but I've some weired and wonderful stuff from DOD/digitech that was switched but ac.. oo


edit
did some google research

http://www.behringer.de/EN/downloads...P0244_S_EN.pdf

Internal, hummm not gonna have one in Maplin, but most likely RS will, "Rodger re-vamp" is a local electronics engineer, especialy with muso kit. I'll see if I can get his email and pm it to you, this would be right up his ally.

peace
cal

Thats the one. There's two VDRs on the PSU board, with no values on them. If I spray them with freezer spray it works for a while, then it starts shutting down again. I might measure their 'cold' value and replace them with fixed resistors and see how it goes. Nowt to lose, useless as it is.

[Calos]

Aye this is the only problem with behringer kit, it's very very good, but quite difficult to repair.

As you are spraying the VDR's, if it's the VDR's then might be worth just replacing them, again it'll be RS for the replacements I think. That said from what I remember, they are there as a safe-guard for the transformer so it could be a case of replacing both to fix the mixer completey


Can't find a schematic to get the values though, again rodger would probabley know what they were. Or waht you can do to negate them and replace the transformer circuit completely, he could probabley make it work with a potato.. I'm not kidding.


peace
cal

[Apache]

I could make it work with a potato too - or maybe two potatoes and a carrot.

However my first choice is to replace what is there if I can find out what values they are. 2nd choice is replace whats there with something less than ideal but which will work. 3rd choice is to measure what voltages it's producing (less the 48v phantom power - dont need that) and design and build a new PSU from scratch.

[MattF]

Pic of the board and the dodgy bits?

[Apache]

Not yet, but if you can help I'll take one tomorrow.

There's a pair of VDRs between a small (high frequency?) multi-tap transformer and a large high voltage capacitor. There isn't any markings on them though.

I HATE switched mode PSUs with a passion. Electrically noisy, unreliable, complicated things, but they use smaller transformers which manufacturers tell us are lighter and run cooler - bollox! Its about cost, plain and simple. Linear PSUs are electrically quiet and technically better. They just happen to cut into profit margins because they require larger transformers for a given current.

Every time someone comes to us for EMC testing and their product features a SMPSU, they fail radiated emissions. They then have to spend a bundle on making it quiet. Should have just gone for a simpler linear one in the first place.

Hmmm ... a nerdy rant. Sorry!

[MattF]

Not yet, but if you can help I'll take one tomorrow.

There's a pair of VDRs between a small (high frequency?) multi-tap transformer and a large high voltage capacitor. There isn't any markings on them though.

Can't promise, but if I get a peek at the unit I might be able to see if it matches up to owt I recognise.

I HATE switched mode PSUs with a passion. Electrically noisy, unreliable, complicated things, but they use smaller transformers which manufacturers tell us are lighter and run cooler - bollox! Its about cost, plain and simple. Linear PSUs are electrically quiet and technically better. They just happen to cut into profit margins because they require larger transformers for a given current.

Hmmm ... a nerdy rant. Sorry!

Oh, it's not a nerd rant. I'm exactly the same. Unreliable pieces of crap too. I can probably count on one hand the amount of transformers I've seen go O/C. Switch modes, on the other hand, practically used to be the bread and butter for a lot of workshops, back in the day. I don't think I knew of any engineer who couldn't repair Pace and Amstrad P.S.U's practically in their sleep due to the frequency of faults.

[Apache]

By the way, did you give me those radios so I could finish pulling out what little hair I have left?

Little b@stards, the pair of them! Did you use them at all? Took me a good couple of hours to program about 70 frequencies that it takes about 10 mins to do on my other radios. Fun, in a tied up and trampled by stilettos kind of way.


Well... no, not that nice

[MattF]

Nah, I never used them personally. I think I once powered them up just to check that they worked, but nothing more. I ain't a geek in that area. Was that clamp any use, btw? I must have had that bugger knocking about for the last ten years or so. I never managed to find a use for it, even though I swore I would. Btw, on the transformer note, I have a decent stash of those transformers if you ever want/need any more.

[Apache]

The clamp is a fantastic bit of kit looking for a use.

The missus will kill me if I screw it to the loft room windowledge though...

[MattF]

You're gonna do the same trick as me and still be saying that years from now, aren't you? It looks cute if nowt else though.