Oops that diode is only good for 100mA I've found out. I'll have to get
some rectifier diodes and try them.
> I tried a 12V nominal (16V measured) adapter with a 1N4148 small signal
> diode attached forward biased to the positive lead. It fired up the gas
> a few times then stopped working. When it did work it kept sparking
> after the gas was lit. I managed to get a voltage masurement, it was
> about 9V.
> ehsjr wrote:
> > suputnic wrote:
> > > Thanks for your input, but as I say below every wall wart works no
> > > problem, and most are rated under 1 Amp. I don't think the diodes will
> > > work because they will have a resistance of a few ohms, and the
> > > resistance needs to be kept much lower than this as John Fields has
> > > noted in a couple of places.
> > >
> > Your reasoning is wrong. Diodes do not have a resistance
> > of a few ohms.
> > You have two alternatives to try - the diodes and the voltage
> > regulator circuit. Report back after you have tried them.
> > You can even get a kit from Dick Smith Electronics - K3594
> > that will give you 3V out with 12V in if you are reluctant
> > to try to build one from scratch. With the confidence you
> > gain from the $6.49 kit, you'll be able to build a regulator
> > from the schematic I posted from scratch.
> > Try the diodes first - they are only 9 cents apiece from
> > Dick Smith - Z3204. Figure 1 volt drop per diode. The
> > exact drop will depend on the current drawn - these 1N4007
> > diodes drop ~1 volt at 1 amp.
> > Ed