hey guys im trying to control speed and direction of the dc motor without any pwm or microcontroller i got this schematic and just need to add DPDT switch to this circuit to controll the direction
You are using the MOSFET in its linear mode.
It will dissipate a lot of heat.
Make sure that you have the MOSFET mounted on an adequately sized heatsink
Um, ok. Was that a request or an observation?
Obviously, you could still use a standard MOSFET H-bridge arrangement, and generate PWM using a suitable oscillator (555 maybe?).
You can also buy off the shelf boards which can do speed/direction control.
Trying to use a MOSFET as a variable resistor by controlling the gate voltage almost never works. There is only a very small gate voltage range, maybe only a few hundred milivolts, where the MOSFET acts like a linear resistor. You will find it almost impossible to adjust the speed manually with a pot.
Time to re-think this project.
Here is a image showing how to wire the switch.
and here is a MOSFET to turn it on/off/PWM.
Connect the battery shown on the switch to the motor connections shown on the MOSFET.
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