need subsituting mosfet advice - Electronic Circuits Projects Diagrams Free

mel8030 · 5th September 2009, 05:52 PM

I have a IRF4905 in a trailer brake controller and a L1404s in a mighty mule gate opener. I have some miscellaneous mosfets. What is the important characteristic to look for in possible subs. Vdss and Id need to be equal or greater and Rds equal or less. What about Vgs(th)?

bountyhunter · 5th September 2009, 08:03 PM

It depends what the drive signal is. If your drive logic is powered from 5V, you need a logic-level FET that turns ON well with 4.5V of gate drive. If your drive circuits swing to 10 or 12V, you don't need logic level FETs but you can use them if you want.

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

Similar
Title	Starter	Forum	Replies	Latest
Need advice! Thank you!	whysolate	Electronic Projects Design/Ideas/Reviews	15	9th November 2007 11:05 PM
need some advice!!!	nye	General Electronics Chat	6	10th July 2006 12:51 PM
Mosfet to ground or mosfet from +v?	bh00	General Electronics Chat	4	23rd May 2006 07:42 PM
Very, very new to this... need advice	testhead1313	Electronic Projects Design/Ideas/Reviews	8	21st January 2006 11:36 PM
looking for some advice...	ultraviolet	General Electronics Chat	19	22nd October 2003 03:39 PM

5th September 2009, 05:52 PM	#1
mel8030	need subsituting mosfet advice I have a IRF4905 in a trailer brake controller and a L1404s in a mighty mule gate opener. I have some miscellaneous mosfets. What is the important characteristic to look for in possible subs. Vdss and Id need to be equal or greater and Rds equal or less. What about Vgs(th)?

5th September 2009, 08:03 PM	#2
bountyhunter	It depends what the drive signal is. If your drive logic is powered from 5V, you need a logic-level FET that turns ON well with 4.5V of gate drive. If your drive circuits swing to 10 or 12V, you don't need logic level FETs but you can use them if you want.