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Slowing a 3 volt motor.
Posted: Wed Jan 27, 2021 5:09 pm
by brian1951
Is it possible to slow down a 3 volt battery operated motor slightly using resistors ??.
Re: Slowing a 3 volt motor.
Posted: Wed Jan 27, 2021 5:28 pm
by Rog (RJ)
Yes but it's better to use diodes as they will give much better voltage regulation. With resistors the voltage and therefore the current will vary depending on the load applied.
Re: Slowing a 3 volt motor.
Posted: Wed Jan 27, 2021 5:54 pm
by brian1951
Thanks Rog.
Re: Slowing a 3 volt motor.
Posted: Wed Jan 27, 2021 6:32 pm
by darkscot
There is an integrated circuit called TDA 7274 that is specifically designed for this sort of application. You need a few other components as well, but if you search for 'TDA 7274 example circuit' or similar you should find lots of examples.
If you have got an old cassette player you might find of of these ICs in it?
Re: Slowing a 3 volt motor.
Posted: Mon Feb 01, 2021 3:28 pm
by brian1951
I have found out through extensive research that what i have been attempting to do, has been tried without success in this set up.
Re: Slowing a 3 volt motor.
Posted: Mon Feb 01, 2021 4:08 pm
by Stese
Hi Brian1951,
out of sheer curiosity... what were you trying to do?
Re: Slowing a 3 volt motor.
Posted: Mon Feb 01, 2021 4:36 pm
by Brian
As Rog (RJ) suggest a simple diode series network will drop the supply volts by 0.7v per diode. You opt for how many are used in the series chain.
If the supply reverses to reverse the motors rotation, you will need a second set in inverse to the first set.
I've shown both options below... Note I've shown three diodes in the series chain but there can be just 1 or more as needed. You can have more or less in one direction to the other too which then allows speed rotation to be different depending on direction.

Re: Slowing a 3 volt motor.
Posted: Mon Feb 01, 2021 4:47 pm
by brian1951
0.7 volt is to much of a drop i think, this maybe one of the reasons the faller car system went over to Dcc control which does give you speed control and a host of other gizmos ( but at a high cost )
Re: Slowing a 3 volt motor.
Posted: Tue Feb 02, 2021 12:01 pm
by brian1951
The 1n4001 has helped with the vehicle i was having problems with thanks Brian & Rog.
Re: Slowing a 3 volt motor.
Posted: Thu Feb 04, 2021 1:01 pm
by Mountain Goat
Question. Though it will obviously heat up, could resistance wire be used? (Just a theory). I am thinking the resistance wire could also be made into a smoke generator so it will do two jobs at the same time. It is just in theory.