HELP with some basic (I think) electronics

ProStreet's picture


Joined: Jun 08, 2019

Replies: 0
HELP with some basic (I think) electronics
June 8, 2019 - 12:42am

I am in NO way an electrician or know ANYTHING about electronics.

I am attempting to run a automotive power window motor CW and CCW.It needs to be controlled buy an Arduino Uno programmable pc board.

The power window needs a good 12v DC supply to work.

The board only puts out very low voltage and amps.

I found a web link showing a possible fix.It uses an automotive 12v DC relay.

But to trigger it, there is a schematic enclosed that I have absolutely no idea how it works.

I believe an auto relay is wired as such# 30   High load input# 85   Switch# 86   Switch#87   High load out

If I use this example, do I bring the load power to pin # 30and the load output power to pin # 87I assume you attach the 1N4002 across the switch (relay coil)

Pin # 86 and pin # 85And I have no idea what the TPI122, the 1N40002 or the 1K Ohm does

All I'm asking is that if I wire it as shown, can I just connect my input and output leads to # 30 and # 87"

I would greatly appreciate ANY and all responses to this postThank You very much

AISHA's picture


Joined: Sep 07, 2017

Replies: 248
Use Relay Module
June 10, 2019 - 11:51am

You are correct. The Arduino I/O pins cannot output enought voltage and current to control a relay directly. It needs a relay driver circuit which consists of a transistor and some resistors. Since you are new to electronics, you can use something called that relay module which consists of this driver circuit built on the module itself. So you can simply power the module and control it with Arduino.

Now that you want to control the motor in CW and CCW direction you would be needing two relay module. Also note that it is not possible to control speed using relays,if you are onto speed control as well then you should use MOSFET in H-bridge configuration.

If you are not into speed control then you can use the relay in following method. As we know reversing the polarity of the motor terminals will change the direction of the motor. So we will need two relays like shown below to change the rotation direction of the motor