Cox Engine Glow Head Voltage?

706jim wrote:Did you actually measure the voltage at the plug when it was connected; that is with a separate voltmeter than you have on the power supply?

2.0 volts will usually burn them out if that's what you actually are getting.

I measured the voltage from the power supply which registered 3V to make it glow red........
then measured it at the glow head as you suggested and it reads just under 1.5V and glows nice and red.
Thank you for that but now I am puzzled...
If two D cells are wired in Parallel we get an output of 1.5V right?
By the time it is measured at the glow head then surely, like my power supply measuring 1.5V, it will not be enough to make the glow head glow red ( ie...1.5V)?
Or are the Cox D cell battery holders wired in series giving an output of 3V and when measured at the glow head we get 1.5V?
Thank you so much for bringing this to my attention.

The length and gauge of the wire leads have a considerable effect on voltage drop. In fact, some modelers use a length of wire to intentionally reduce voltage from a 2 volt wet cell to 1.5 volts at the plug. So voltage drop is what I think you're seeing particularly if the wires are thin and/or long. As fire as I know the Cox battery holders were wired in parallel to give 1.5 volts.

I use just one sub c batry and it work Fine it just light longer wit two batry in parallèle positif To positive négative To négative ... To never over volt i use sub c rechargeable batry as its 1.2 v it cant over volt glow plug but in the Canada cold has difrent meaning here the word cold takes on another meaning and somtime its hard To light that glow plug so we use 1.5 v c batry a new 1.5 work bether than a rechargeable 1.2v battry

Use short battery cables. It works.

Thanks for your answers. They were very helpful.
I checked the Voltage out from the bench power supply at circa 3V and at the plug end it was 1.5V so all okay.
Thinking about it there will be a voltage drop as it has to travel through the wire ( Not so massive) but by the time it heats the filament to glow red then of course that explains a voltage loss?
Think I may be right there but will stand correction.

Woody wrote:Thinking about it there will be a voltage drop as it has to travel through the wire ( Not so massive) but by the time it heats the filament to glow red then of course that explains a voltage loss?
Think I may be right there but will stand correction.

Yes, right.