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How to wire a 12v motor and limit switches to raise and lower a satnav panel in my car,using the ignition switch circuit

Hi,
I'm trying to understand in a simplified diagram how to use a 12v motor to raise and lower a panel in my car,the hardware I can make fairly easily but it's the wiring I'm struggling with,I understand that 2 limit switches have to be used to stop and start the motor,also that the polarity of the motor has to be changed to raise and lower the panel,
I also want to use the vehicles ignition switched circuit to raise and lower the panel as opposed to using a rocker switch,
Any help in this matter would be greatly appreciated,
Kind regards,
Darren.

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AbhishekR9010 months ago

Hi steveastrouk, i know this post is really old but i'm trying to replicate the circuit you have shown below but i cannot get the simulation to work properly. Can you please let me know what are the actual values of the resistor and capacitor to be used as the the first two relays are showing as exploding when turned on. Also, please let me know where all i need to use current limiting components in the circuit since the simulated current is over 230amps. Please let me know if i'm doing something wrong.

Also i was trying to figure out how the third relay needs to be wired to the ACC terminals. Do the first two relays need to be powered by always on 12v battery supply?

Additionally, in the ignition switch on position and during one of the rotation of the motor (CW or CCW), the current does not flow through the bridge. Is that normal and expected?

AbhishekR9010 months ago

steveastrouk, can you please look at the attached circuit diagram. I got how to wire up the third relay but still dont know what other components i need to use to limit the simulated current shown in the software. Have i wired up everything correctly?

There are two circuit images, one is with the ignition switch off and the other is with the ignition switch on.

My query now is how do i stop the flow of current from battery through the bridge? This can potentially drain the car battery isn't it?

When Ignition switch is off.PNGWhen Ignition switch is on.PNG
Darren,

Here's a circuit I ran up for a fellow Instructable member. It takes THREE relays with this circuit - the "bottom" relay would be held on by the ignition circuit.
Hen door.jpg
Rallyingace (author)  steveastrouk6 years ago
Hi,
Many thanks for the quick response,
But can I try and understand it better by listing the components and ask you to fill in the blanks as my understanding of this schematic is limited,

Relay 1;
Pin 30 =
Pin 85 =
Pin 86 =
Pin 87 =
Pin 87a =

Relay 2;
Pin 30 =
Pin 85 =
Pin 86 =
Pin 87 =
Pin 87a =

Relay 3;
Pin 30 =
Pin 85 =
Pin 86 =
Pin 87 =
Pin 87a =

Limit Switch 1;
NC =
NO =
Common =

Limit Switch 2;
NC =
NO =
Common =

Also what is a W04G Bridge?

Sorry if this seems trivial to you but I'd really like to nail the understanding of this,
Thanks in anticipation,
Darren.

I haven't got the time to pick through the whole circuit and re annotate it I'm afraid.
But, for an automotive relay
A relay My reference
Pin 30 = 3
Pin 85 = 7
Pin 86 = 8
Pin 87 = 5
Pin 87a =1

The limit switches should be wired "Normally closed", so that when the load reaches them, it OPENS the switch.

Play with it, and DON'T connect the motor to the load until you have verified the motor goes the right way with the right switch - all you need to do is reverse the motor wiring.

Steve

Rallyingace (author)  steveastrouk6 years ago
Many thanks Steve, I'll have a play,
Cheers....
Sorry, the switch marked "changeover switch in timer" would be the third relay.

Steve
I like how you suppressed the bidirectional motor kick !   A
Thanks !