double coil latching relay for motor control

Hey Forum,

I would like to control a window screen motor 5A/250V, up/down, using the arduino. So the relay is your option. Lots of research later, I found that most options need continuous power to the relay (5V) to keep the screen in a certain state, which I find a bit odd. Also the electronical (bistable) latching relay draws continuous power, even though small, still.

Solution: Double coil latching relays like here

This module is based on 2-Coil Latching Relay. Contrast to the ordinary relay, this latching relay does not need continuous power to keep the state, only a rising/falling pulse is needed to change the work state. Even the power can be removed when the work state do not need to change, making this module especially suitable for low-power projects.


  • is the double coil relay the only option for steady state no power consumption through relay?
  • does this module exist in a pre-wired board to be used with arduino using 5A/250V output relay?

thanks for your time and energy

I found that most options need continuous power to keep the screen in a certain state

With a 250v motor, I would not expect this to be so.

We need more information on the equipment and setup.


lots of cross information. first off, the motor you list is 5 amps. the relay you link are 1 amp at 230v.

second, a relay acts like a switch. you apply power and it changes state. now your motor would have full power, 5 amps at 230 volts. there is no means to reduce that except to turn the motor off completely. but that would mean you need two such relays, one for up, the second for down.

still no partial power while at rest.....

if you have a 3rd relay that feed either full power or partial power, then you could wire up the motor so that the high/low could feed each of the other two.

but, no you have the problem that it is possible to have both up and down energized at the same time.
that is, unless you add a 4th relay that sends power to either up or down....

OK,. let's start again.

one relay that feeds either up or down.
one relay that feeds the first relay, either high or low power

now, one motor will always get power, either high or low.

not liking this all that much. I think some thought to how this would work is in order.

thanks so much already for your time in posing response :slight_smile:

The 'no power consumption' happens in the relay itself. It is the set/reset functionality I was looking for. The relay functions on a pulse, rather then a current. The pulse from the arduino sets the relay in certain state and this, in it's turn, stays that way.

The 5A/250V motor itself is auto-regulating. Once down (or up) reaches certain level, it breaks its own circuit, 'listening' for the up(or down) 'command' (read: voltage going high or low, you get the point).

I was wondering if the board setup, with the 125V solution from, would also exist in the 250V

to put it in a schema:

arduino -> pulse -> relay -> flick -> down circuit closed -> motor -> bzzzzz -> auto off state -> click -> Stop

=== No Power Consumption

and obviously vice cersa:

arduino -> pulse -> relay -> flick -> up circuit closed -> motor -> bzzzzz -> auto off state -> click -> Stop

=== No Power Consumption

hope this clarified it better?! It all makes perfect sense when it is posted in your head. Trying to get the message across is always the challenge.

There is a Forum Law that answers are only as concise as the question.

but that if you knew everything needed to form the exact question, the best way, you would know enough to answer it.

the motor has internal end switches. very common.

what it sounds like, is that when you apply power to the UP side, the blinds go up, until the switch is made, then stops.because a switch is opened, taking power from the blinds motor.

a manual switch is all that is needed, but no fun.

you are correct that a latching relay could work, that is something you can do with an Arduino. the relay you linked was not rated for the correct amps, so is not a good choice, but latching relays are available for your needs.
I think you will find them in 12v or more, that 5v coils are a bit harder to find.

but that should not be a problem, we can help you switch any coil voltage you get. may need a second relay....

As an option, and lots more work, but you could add a current transducer to the power for the motor. you want it to go up. you turn on a regular relay, the motor goes up and power is used. the motor reached the limit, no power is used. you see that no power is needed and you take the power off the coil of the regular relay. it would require two relays, but non-latching are cheap.