7810 output voltage spiking?

[danial stocks]

>Some 78xx regulators *do* output a higher voltage
>when there is no output current. Maybe your
>switched regulator doesn't draw current in the first

I dont think this is the problem... most reg/smps chips do expect a little 
surging on the inputand so are at least a bit protected against this.. even 
if not, the surge if it is going to damage should do it pretty immediately, 
not in 15 mins.. I'd be looking for something close to failure time.. Dont 
know of the actual setups for the LTC1044 chip, but if using inductor in 
system maybe consider that wrong inductance is causing excess current 
consumption - a too small val can cause a high idle current.. does the chip 
run hot before failing?
Cheers,
Dan
>
>-----Ursprüngliche Nachricht-----
>Von: Rob <cyborg_0 at iquest.net>
>An: Synth-DIY list <synth-diy at node12b53.a2000.nl>
>Gesendet: Samstag, 21. Oktober 2000 20:19
>Betreff: 7810 output voltage spiking?
>
>
>I have a problem.
>
>I have a power supply that has a 15 volt input supplying voltage to a 7810,
>then, I take the 10v out from there and put it into an LTC1044A. But, for
>some reason, after being on for about 15 minutes, the LTC1044A dies.
>
>BTW, the 1044 is a switching type regulator.
>
>Now, my question is, could the 7810 be allowing a spike on power-on to get
>past regulation and damage the LTC1044A? I would think it unlikely, but I 
>am
>wondering if anyone has had such experiences with this sort of thing.
>Changing the LTC1044a merely smokes another LTC1044a.
>
>I am seriously believing its this 7810, but, the 7810 does not seem to be
>out of regulation, on the contrary is is holding a very solid 10 volts
>exactly according to my recently cal'd scope.I have not been able to 
>capture
>the power on spike either.
>
>What gives?
>
>Rob
>
>
>
>

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