RMS or average current to determine resistoring heating?

"Mook Johnson"

** If you want to build the BEST glow plug driver possible

- see ABSE under " Glow Plug Regulator ".

This circuit regulates the TEMPERATURE of the platinum wire under all conditions, whether the plug is dry and out of the engine, wet with fuel or if the engine is idling or screaming.

The amp meter will allow you to tell if the plug is wet, blown, the mixture is too lean or too rich.

What luxury - eh ?

I used one for many years, it really helped with getting quick engine starts and consistent mixture settings.

....... Phil

Really? And you call this "dramatic," like there has been some kind of current amplification effect taking place there, the battery supplying one current and the glow plug seeing another? Since the current is the same everywhere in the circuit, the battery and glow plug currents are the same. The battery supplies 0.5A average, and the glow plug receives

0.5A average, and conversely, in order for the glow plug to receive 5Arms, the battery must supply 5A,rms. Where is the miracle there? In any pulsed current system, Iavg=Ipk*D, and Irms=Ipk*sqrt(D) so that Irms/Iavg=1/sqrt(D) which is always >1.

Sweet circuit.

I'll have to give it try.

pretty much:

perhaps you meant: Irms = Ipeak *sqrt(duty cycle) for a square wave....

thats quite an impressive typo :)

Actually, aside from being wrong, its also dreadfully ambiguous (use average what?), which will doubtless confuse most who read it.