"....You could smooth the pulses with a capacitor to keep the voltage up - a bit or experimentation may be needed (1uf?)..."

Just had a go at this with a Taycol Target on 7.2v - you get a noticeable brightness increase at .5uf - but noticeable isn't the same as useful! 1-2uf is better. 10uf is at the limit, because much more smooths the pulses out so much that the motor runs at fairly full power! I had guessed at 1-10uf earlier, but hadn't thought about what the armature would do with a constant high voltage...

It would be more elegant to isolate the indicator circuit by latching the led and resetting as the power went through zero. Or detect revolutions directly with an optical interrupt. Or a frequency-to-voltage converter... but now we are talking about electronics as a hobby rather than model boats... 🤕

If the reason for an LED indicator is that you want to be able to tell when the motor is still going, but very slowly, then a simple LED will not be very bright when the pulse rate is low.

You could smooth the pulses with a capacitor to keep the voltage up - a bit or experimentation may be needed (1uf?) - or go the whole hog and use a latching circuit, perhaps with a 555?

Hi Doug,
Luckily I have two of these that I plan on using when I eventually do the modifications to HMS Cottesmore.

Martin.

Now that's an easy one at last Michael 😉
Since it's a brushed motor simply put a two colour LED (Red / Green), with a 1K to 2.2K (for higher drive voltages) resistor in series, across the motor supply leads.
If you want the indicator above deck just extend the wires from the LED.

I have mine arranged to show green for ahead and red for astern.
If the motor rotation is correct but the colour wrong just turn the LED round 👍
I put my LEDs in a small two pin PCB type socket.😁

If you don't want to fiddle with the soldering yourself get some of these-
https://www.componentshop.co.uk/p95-indicator-fuse-boards-single.html
This little board has the advantage that it also has blade fuse holder built in.
Not difficult to make your own on Vero Board though😉
Cheers, Doug 😎
BTW Haven't tried this with a brushless yet, but now I'm curious! Always dangerous 😁