Help Need a Circuit for a Micro Timer Motor control

Thread Starter

george0039

Joined Oct 15, 2008
167
Bernard Thank You for helping me with this. I will have to get the FET as I don`t have that in stock. Also if anyone can show me how to post a video OR picture of my project here I would appreciate it. Please follow the KISS principle with your instructions.

Thanks again
George
 

Thread Starter

george0039

Joined Oct 15, 2008
167
Hello

I don`t know if it o.k or not but with the circuit above, when I use brushed motors in R.C uses, I always put 3 - 0.1uf across the motor terminals and case and across the terminals to control brush noise interference. Is that o.k to do here?
Add a freewheel diode across the motor?
 

AnalogKid

Joined Aug 1, 2013
9,609
Noise spikes from commutation and back EMF from the turn-off transient contain a lot of high frequency energy. All wiring and capacitors have some inductance, and that inductance acts to decrease the effectiveness of the capacitor as part of a noise filter circuit. Electrolytic capacitors have a wound construction that naturally increases the ESL (Equivalent Series Inductance). Also, the dielectric has a much higher impedance at high frequencies compared to the various ceramic and film types. Also, you wouldn't think an extra inch of lead inductance would matter, but its effect is measurable.

ak
 

Thread Starter

george0039

Joined Oct 15, 2008
167
Well I have to put this project aside for now. Went to my local electronics parts shop, no luck, no cross reference. So I have gone through ebay China. Should be here in a couple weeks. Then onward.

Thanks again for the help.

IF there is any new developments, I`m ALL eyes.
 

Bernard

Joined Aug 7, 2008
5,788
With a bigger motor, Johnson 63716, 35 mm X 55 mm, 2A @ 3V. retried FDD6530A, & 2 darlington transistors
D1326 & 2N6037 which both ran hot with saturation V over 1 V while the FET ran cool with 2V gate, & .15 V
saturation .
 

Thread Starter

george0039

Joined Oct 15, 2008
167
With a bigger motor, Johnson 63716, 35 mm X 55 mm, 2A @ 3V. retried FDD6530A, & 2 darlington transistors
D1326 & 2N6037 which both ran hot with saturation V over 1 V while the FET ran cool with 2V gate, & .15 V
saturation .
Hi Bernard

Thanks for the update BUT I have no intention of going to a larger motor, weight, size are my limiting factors and there is no need.
Thanks again for your help.
George
 
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