6
votes
Diodes not protecting MOSFET from avalanche current
First, leaving the gate which is a high-impedance node, should never be left open like that. It's not surprising your blowing out transistors under this operating condition. The gate should be tied to ...
- 6,747
2
votes
Diodes not protecting MOSFET from avalanche current
The motor can easily take very high current at the startup (depends on the available voltage, all series resistances and the inductance). 5 times higher starting current than the current in normal ...
- 31
2
votes
DC Motor regulated with cheap PWM regulator make electrical noise
I agree with the other answers that filtering is likely the best approach. Another option to consider is switching to shielded wiring, with the shield connected to ground.
I ran into a similar issue ...
- 21
1
vote
DC Motor regulated with cheap PWM regulator make electrical noise
Both motors with commutators and PWM speed controllers make pulses with fast rise and fall times, creating electrical noise. Filtering that noise is simple.
Add a filter choke or a ferrite filter ...
- 6,373
1
vote
DC Motor regulated with cheap PWM regulator make electrical noise
The regulator is not dead : PWM running along wires makes for a great radio transmitter. The motor will make a tone based on the base frequency of the PWM. Those PWM controllers are crude.
You need to ...
- 354
1
vote
Control current with voltage
linear is like this, but will make a lot of heat in the Q1
simulate this circuit – Schematic created using CircuitLab
- 40.5k
1
vote
How can I increase the current being supplied to a model railroad locomotive?
You either need a more powerfull controller (>= 8A). Or, you have to up the voltage. You can't have it both ways (unless the 4A controller is starving the train and the voltage is sagging without ...
- 6,747
Only top scored, non community-wiki answers of a minimum length are eligible