BJT or MOSFET - Electronic Circuits Projects Diagrams Free

mahmoud shendy · 2nd January 2008, 12:02 PM

Dear all, we have in our lab an inductive load that has an internal esistance of about 25 Ohm, it is required to
varying the DC current through that coil from 0.5A to 5.5A to perform its operation, and so i think in PWM that switch
this inductive load ON and OFF from a 150 VDC supply and by varying the DUTY CYCLE of the PWM circuit, we can then adjust
the average DC current... Now is this right or not, and if this is right what is better to switch this load BJT or MOSFET
. by the way, the inductance of this load is neglectible..

I read about the TIPL755 and in its datasheet listed that it is for fast inductive load switching. is it better or using
power MOS such as BUZ45..

( i forgot in this schematic the free wheeling diode, but it is already placed )..

am waiting for your helpful replies, thanx in advance......... M.Shendy

Styx · 2nd January 2008, 10:47 PM

go for a FET, easier to work with

Hero999 · 2nd January 2008, 10:49 PM

What's your question?

Use a power MOSFET with a high enough voltage rating.

If you know the inductance you can calculate the rate of rise and fall of the current in the coil depending on the frequency and duty cycle.

mahmoud shendy · 3rd January 2008, 10:59 AM

thanx a lot for your help, thanx again

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Title	Starter	Forum	Replies	Latest
pic and mosfet interface	h.d	General Electronics Chat	16	11th December 2007 09:18 PM
PIC and Mosfet	Barry	Micro Controllers	3	2nd October 2004 03:29 PM
MOSFET Relay problem	guilio_2000	General Electronics Chat	16	10th August 2004 05:33 PM
Here is a list of semiconductor prefixes.	TPS	Datasheet/Parts Requests	0	21st December 2003 08:24 PM
Identify Semiconductors by prefixes	mixos	Datasheet/Parts Requests	0	10th December 2003 07:56 PM

2nd January 2008, 12:02 PM	(permalink)
mahmoud shendy	BJT or MOSFET Dear all, we have in our lab an inductive load that has an internal esistance of about 25 Ohm, it is required to varying the DC current through that coil from 0.5A to 5.5A to perform its operation, and so i think in PWM that switch this inductive load ON and OFF from a 150 VDC supply and by varying the DUTY CYCLE of the PWM circuit, we can then adjust the average DC current... Now is this right or not, and if this is right what is better to switch this load BJT or MOSFET . by the way, the inductance of this load is neglectible.. I read about the TIPL755 and in its datasheet listed that it is for fast inductive load switching. is it better or using power MOS such as BUZ45.. ( i forgot in this schematic the free wheeling diode, but it is already placed ).. am waiting for your helpful replies, thanx in advance......... M.Shendy Last edited by mahmoud shendy; 2nd January 2008 at 12:05 PM.

2nd January 2008, 10:47 PM	(permalink)
Styx	go for a FET, easier to work with __________________ Nothing is impossible. Once a problem is realised, the rest is just details

2nd January 2008, 10:49 PM	(permalink)
Hero999	What's your question? Use a power MOSFET with a high enough voltage rating. If you know the inductance you can calculate the rate of rise and fall of the current in the coil depending on the frequency and duty cycle. __________________ I also post at the following sites: http://www.stop-microsoft.org http://www.heated-debates.com Screen name: Aloone_Jonez

3rd January 2008, 10:59 AM	(permalink)
mahmoud shendy	thanx a lot for your help, thanx again