I used a one shot short delay relay circuit a while ago, but it is easily modified as shown.
I used Omron ice-cube relays, MY4ZN for 24vdc, for this circuit you would need both 24vdc and 12vdc coil.
R1 & R2 equals RLY2 & RLY4 coil resistance.
Max.

 

So far there has been no mention of H bridge or electronic switching?
Max.

Who said anything about electronic switching. I was suggesting he use a DPDT relay wired as an H-bridge (i.e. reversing relay)

 

Replace the pushbutton with a simple DPDT switch (break-before-make is essential, so most switches will be ok but you could use a centre-off type to be sure) and this should work. It relies on the break action during switch changeover to trigger a 1/2 sec monostable made from the CD4000. C2/R7 determine the 'on' time. R1-R4 are voltage dividers to avoid stressing the gate inputs of U2a (but you could probably omit R2/R4).

 

Hi Minkey01,

Here's a circuit using a 555 and a relay 'H' Bridge.
Regards,

Nandu.

Won't that keep the coil energized when the relay is off?
A pulse only is required.
Max.

 

Hi Minkey01,

Here's a circuit using a 555 and a relay 'H' Bridge

That will burn up the latching solenoid.

 

Just to be clear. The + pulse should only stay on for milli seconds. The same with the - pulse. It holds in with a permanent magnet that doesn't need any power after the initial pulse. Pick and drop they were calling it. Any pulse longer than 1 sec will probably burn it up. The spec sheet says 1 sec max, so we want to stay away from that.

This is for a tape cassette play button. The application will work like this. The solenoid will only pull in a lever with a 10 mm or so stroke. Somewhere within the last 0.5 mm the rubber pinch roller will end up pressing against a shaft. This pinch force should be around 8.25 lbf. Before that it is just the weight of the lever arm and the reverse force of that return spring shown in the specs. The duty cycle is very small, as you can imagine. Hit play and then it might be hours before the disengaged is hit. This is the reason for the latching type. The long hold time does not require any power being sent.

If it is easier to have one button be the play and another the stop, I'll do it. I just don't want someone to be able to hold a button down and burn up the coil.

 

That is the premise behind the PDF I posted, after the initial energize pulse, (either direction), the PB for that direction is inhibited from having any effect if pushed or held pushed.
Max.

 

That is the premise behind the PDF I posted, after the initial energize pulse, (either direction), the PB for that direction is inhibited from having any effect if pushed or held pushed.
Max.

nice! i like it.

could those relays be replaced with ic parts? i'm unfamiliar with those ice-cube relays and seem a bit large.

 

nice! i like it.

could those relays be replaced with ic parts? i'm unfamiliar with those ice-cube relays and seem a bit large.

would need some diodes added too for the flashback protection?

 

nice! i like it.

could those relays be replaced with ic parts? i'm unfamiliar with those ice-cube relays and seem a bit large.

Typically not for two reasons:

1. Creating a coil (inductor) in an IC is an impossibility.
2. Maintaining the contact state in a power off condition cannot be done.

The function can be approximated, but not duplicated. That said, there are low voltage relays that can be mounted on a PC board that look like an IC but slightly larger.

 

In this case a power off condition does not matter, as the solenoid remains in the last state, either mag or de-mag.
Another option would be a Smart Relay, these should virtually simulate the coil relay circuit.
They are made and relabeled by quite a few manuf. and in some cases the software is free.
Siemens, Idec, Square D, Omron.
Max.

 

Where is the reverse, Latch/Unlatch pulse?
*:I see, the Cap discharge.
Max.

 

The C value in that post #33 circuit would need to be HUGE. This solenoid draws up to 2A (for less than 1 sec)!!

Edit: If this solenoid is going to be used for operating a 'start' key on a tape deck, won't you need a second solenoid to operate the 'stop' key? Tape deck keys are usually self-latching. That being so, I'm unclear why you need a latching solenoid.
What will you use for the ~28V supply?

 

Obviously you didn't like my option using a DPDT switch . If you wish to keep the button switch and avoid relays here's how you could do it. The 4013 is configured as a monostable with an 'on' duration (here ~160mS) set by R2/C1. Each press of the button toggles the state of U1b's outputs to switch the FET H-bridge. Q1 and Q2 are level-shifters, with voltage dividers in their collector paths to limit the Vgs applied to the high-side P-FETs. R3/C2 provide a ~1mS delay to enable the bridge to settle before FET M5 switches on to power the solenoid. This delay prevents 'shoot-through' current in the bridge.

 

The C value in that post #33 circuit would need to be HUGE. This solenoid draws up to 2A (for less than 1 sec)!!

Edit: If this solenoid is going to be used for operating a 'start' key on a tape deck, won't you need a second solenoid to operate the 'stop' key? Tape deck keys are usually self-latching. That being so, I'm unclear why you need a latching solenoid.
What will you use for the ~28V supply?

no no. the solenoid pulls the rubber pinch roller into the capstan shaft. the capstan shaft spins from a motor thus moving the magnetic audio tape.