doncarlosalbatros
Full Member level 2
I need to PWM control two electromagnet groups where each group has four electromagnets. Emagnets have nominal 24V 0.33A current ratings. **broken link removed** is the only datasheet I could find. To supply all the magnets I want to use this 24V 4.2A single power supply. To model these, I drew the schematics as follows:
Above each RL series represents an electromagnet. There are total 8 magnets. To model emagnets each drawing 0.33A current, I used 72Ohm and 1u inductor. I also added 1N4148 as a flywheel diode to each magnet.
The idea is two PWM outputs of a micro-controller like Arduino's will control(by two potentiometers as analog inputs of the uC) each two groups's MOSFET gate hence the magnet strength. This MOSFET is a logic level MOSFET.
The electromagnets are supplied by a 24V 4.2A power supply. The uC(Arduino board in this case) and the **broken link removed**non-inverting driver will be supplied by a 9V adapter.
In simulation I obtain the following power plot(and the peak current is around 1.4A) for this MOSFET I plan to use:
Before I start soldering I would like to know your suggestions about the circuit for this application. I should for instance figure out if I need heat sink. I afraid these magnets might make ringing noise so if I increase PWM to 30kHz(to eliminate noise) the FET's power dissipation will be high. Currently the PWM freq. is 500Hz. At what PWM freq. these MOSFETs would require heatsink?
Is it fine to use TC427 with 9V supply and trigger the MOSFETs gates this way?
I would be glad to hear your opinions/suggestions.
Above each RL series represents an electromagnet. There are total 8 magnets. To model emagnets each drawing 0.33A current, I used 72Ohm and 1u inductor. I also added 1N4148 as a flywheel diode to each magnet.
The idea is two PWM outputs of a micro-controller like Arduino's will control(by two potentiometers as analog inputs of the uC) each two groups's MOSFET gate hence the magnet strength. This MOSFET is a logic level MOSFET.
The electromagnets are supplied by a 24V 4.2A power supply. The uC(Arduino board in this case) and the **broken link removed**non-inverting driver will be supplied by a 9V adapter.
In simulation I obtain the following power plot(and the peak current is around 1.4A) for this MOSFET I plan to use:
Before I start soldering I would like to know your suggestions about the circuit for this application. I should for instance figure out if I need heat sink. I afraid these magnets might make ringing noise so if I increase PWM to 30kHz(to eliminate noise) the FET's power dissipation will be high. Currently the PWM freq. is 500Hz. At what PWM freq. these MOSFETs would require heatsink?
Is it fine to use TC427 with 9V supply and trigger the MOSFETs gates this way?
I would be glad to hear your opinions/suggestions.