dc motor with mosfet

can i control a 24V 250W dc motor speed with 555 timer using power mosfet

sure you can

Here is an example



It's not using 555 but it's just to give you an idea

For controlling inductive power devices, it is preferable perform driving using devices such as IGBTs or BJTs, Unlike power MOSFET, these ones have an intrinsic silicon structure which brings higher breakdown voltage, turning it less susceptible to burning.



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I support your post. It is also true that for high voltage (600V) there is no yet MOSFET with high current capability.
Track drivers use just only IGBT modules. Also we have to think about reliability. IGBT has hight reliability and we could trust them.

However in this case the OP wants to switch 24V, so a MOSFET would be fine.

Unlike IGBTs and BJTs, recent power MOSFET have avalanche capability and can absorb overvoltages with limited energy safely. Nobody would use IGBTs for a 24V switcher due to inacceptable high saturation voltage.

The circuit in post #2 is fine, except for missing power supply bypass capacitors. Low inductance film capacitors should be placed near the output transistors and freewheeling diodes in a low inductance layout.

High voltage/high power switcher is a different topic. Presently, MOSFET can compete up to 600, maximum 700 V DC bus and a few 10 kW. SiC FET will probably extend the applicable voltage range in the near future.

There is a relevant application note from International Rectifier **broken link removed**

MOSFETs and IGBTs: Similar But Different
The IGBT technology is certainly the device of choice for breakdown voltages above 1000V, while the MOSFET is certainly the device of choice for device breakdown voltages below 250V.
Between 250 to 1000V, there are many technical papers available from manufacturers of these devices, some preferring MOSFETs, some IGBTs. However, choosing between IGBTs and MOSFETs is very application specific and cost, size, speed and thermal requirements should all be considered.

IGBTs have been the preferred device under these conditions:

• Low duty cycle
• Low frequency (<20kHz)
• Narrow or small line or load variations
• High-voltage applications (>1000V)
• Operation at high junction temperature is allowed (>100°C)
• >5kW output power

MOSFETs are preferred in:

• High frequency applications (>200kHz)
• Wide line or load variations
• Long duty cycles
• Low-voltage applications (<250V)
• < 500W output power

Click to expand...

**broken link removed**