Thank you Dg,
It was a question that somebody asked me and I said that I would ask on this site.
Thanks again.

Martin555.

Unless you have all the parts immediately you will find it difficult to make for the cost of one shipped from China!

If you need it immediately, you will need to source it in this country, of course. Here is one at twice the Chinese price - £2.03 to be precise - which is in the UK and should be with you by the end of next week.

https://www.ebay.co.uk/itm/1-8V-3V-5V-6V-12V-2A-Low-Voltage-Motor-Speed-Controller-PWM-1803B-M216-In-UK/113865219980?hash=item1a82e55f8c:g:77EAAOSwi0RbG4WB

If you look closely you will see an NE555 on the board!

Excellent thank you Fleet.

Martin555.

A 0.1uF (100,000 pico Farad. 10 with four 0s!)) ceramic capacitor Martin
Yes, that cct will do the job nicely. At very low speeds you might need to tweak the prop to get it started. Or start fast and slow it down a bit.
😎

Hi Dg,
Have just found this, would this do the trick ?
what is the 104 cap ?


Martin555.

We have covered this before - dropping volts at low power is probably best done with diodes in series.

But if you want a motor to move very slowly you probably don't want to drop the volts - to get a very slow speed you may need such a low voltage that the motor can't overcome bearing friction.

In this case you use pulse width modulation. You send a signal which has full volts for, say, 50% of the time and 0 volts for the rest. That gives you 'half power' - but the motor is given enough volts to be sure of getting it moving.

This technique is used by the model railway boys for slow speed when shunting. So... something like this?
https://www.ebay.co.uk/itm/Mini-DC-5A-Motor-PWM-Speed-Controller-3V-35V-Speed-Control-Switch-LED-Dimmer-new/191885437600?epid=20008384776&hash=item2cad436aa0:g:bFQAAOSwEIJbnMMk

I wonder if a variable resistor on the input supply might do the trick. That would be some reduction though for making a safe rotational speed. Doug will have the answer.😀