Isolated IO MOSFET Boards - Page 1
Forum section: electronics / beginners

author: Remark
author_rank: Contributor
timestamp: February 17, 2023, 09:13:00 pm
content: Hello everyone!I have to control 8 12vdc brush motors with 12v valves. I'm wondering if there are mosfet modules on the market for power control? In which it would be possible to connect a logic signal from a microcontroller and connect motors with valves at the output... PWM control is now unnecessary.Maybe someone has tried and tested something similar from them?Thanks for the answers!Remark.

author: Zero999
author_rank: Super Contributor
timestamp: February 18, 2023, 11:43:09 am
content: How much current? Do they have free-wheeling diodes? What degree of isolation is required?Why not simply use relays? If frequent switching is required, or there's lots of vibration, go with solid state relays. Automotive relays are a good option for high vibration, but don't provide as much isolation as mains rated relays.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 18, 2023, 12:00:15 pm
content: Also needed to know is the voltage the microcontroller is running on. 5V, 3V3 or something else.Does the isolation need to be optical or is the gate of a FET isolation enough. Do the motors need directional control or just on/off.Please paint us the full picture, with actual pictures because we do like pictures.

author: Remark
author_rank: Contributor
timestamp: February 20, 2023, 07:24:15 pm
content: Quote from: Zero999 on February 18, 2023, 11:43:09 amAbout 1.5A through one motor. No, there are no free wheeling diodes at all. I am afraid to use the relays because of the noise it makes (I'm talking about mechanical ones). I did not find the correct current for the SSR relays, there are only small current ones... Talking about the isolation, preferably optical...

author: Remark
author_rank: Contributor
timestamp: February 20, 2023, 07:30:46 pm
content: Quote from: pcprogrammer on February 18, 2023, 12:00:15 pmMicrocontroller is running on 3.3V. I think isolation needs to be optical or FET isolation. And I need just to turn on and off one motor by one or turn on all 8 motors at once.I found something similar but only 4 channels:https://www.aliexpress.com/item/4000591609616.htmlwill try to find more.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 20, 2023, 07:37:41 pm
content: Get two of those modules and you are thereIt is easy to turn them all on at the same time using software.The module seems to have a RC snubber on it so that is good too.

author: Zero999
author_rank: Super Contributor
timestamp: February 20, 2023, 09:00:01 pm
content: Quote from: Remark on February 20, 2023, 07:24:15 pmThe motor's noise, both electrical and mechanical will probably be much worse, than that of the relays.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: February 22, 2023, 11:42:44 am
content: Search for "optomos relay". These are optocouplers with a small solar cell at the output, and these can generate a voltage to drive a MOSfet.

author: BadeBhaiya
author_rank: Regular Contributor
timestamp: February 23, 2023, 08:10:18 am
content: Quote from: Doctorandus_P on February 22, 2023, 11:42:44 amI know them as "Gate drive optocouplers". For such a handy part, they sure are not well known