Hi all I’m having a blank moment today
I have a latching pull solenoid that in normal state is latched until voltage is reversed to release
I have a 5 volt control tof timer swiching 24v dc to pull the flap down to its latched state but req the voltage to be reversed to unlatch to allow the flap to open again
Any ideas on how I can reverse the voltage for 2 ms thinking of using a flip flop relay but my mind is blank ?

If anyone has any ideas it will be great appreciated
Simon

 

Maybe like this?
Pressing Sw1 allows a manual release of the solenoid. The value of C1 will depend on the coil resistance of RL1 a 24 volt DPDT relay.

 

Maybe like this?
Pressing Sw1 allows a manual release of the solenoid. The value of C1 will depend on the coil resistance of RL1 a 24 volt DPDT relay.
View attachment 329990

Thank you this could work
I have a end of travel sensor that outputs 5 v I could use this signal to reverse the signal with a delay timer in reverse of the first timer
Thanks for the advice

 

How soon do you need to release the solenoid when the travel sensor outputs 5 volts?

 

How soon do you need to release the solenoid when the travel sensor outputs 5 volts?

I would say it is between 50-100ms

 

I would say it is between 50-100ms

Could do that with a simple circuit if need be.

 

How soon do you need to release the solenoid when the travel sensor outputs 5 volts?

I have just just ordered a DPDT relay I believe looking at the process I believe your on the right track
Thank you so much for your support

 

Is that module the timer and how is it controlled by a 5v signal?

 

Drive it with an Allegro A4953 or Toshiba TB67H450 using this circuit. The RC time constant should be 2ms. Don't use a low-value resistor as there is a 220k pulldown on the IC.
When the input voltage goes high it delivers a 2ms pulse to close the solenoid, when the input voltage goes low it delivers a 2ms pulse to release it.

 

Is that module the timer and how is it controlled by a 5volt signal?

No the delay timer is currently triggered via 24v then if I connect it to this motor controller I will be able to use the cycle end sensor 5v signal to momentarily flip the polarity releasing the solenoid to open the flap again I will draw my idea out for you unless you have a better idea

Just as a breakdown
I have a flap when the machine is in it’s moving cycle the flap needs to be locked down once the cycle has completed then the flap is free to move under its own weight
The latching solenoid is only to pull down the flap and lock it in place eliminating access to the moving parts
The drive from the motor controller has two cycle sensors bottom and top of cycle both 5v hence why I want to trigger by 5v so as the cycle starts and leaves the top sensor and completes it’s movement of 350ms then is released by the bottom sensor but due to travel I have to hold the solenoid on until the cycle has been completed then there is a 50-100ms before the second drive moves the item through the flap hence needing to release the latch
Hope this helps

 

I will draw my idea out for you unless you have a better idea

Would like to see that drawing.

 

To deliver a controlled 2 millisecond reversed polarity pulse will require a circuit called an "H-Bridge", and a suitable driver circuit. Quite common but not so simple.

 

All that is required is an electrolytic capacitor.

In one position of the switch, the capacitor charges through the solenoid coil and in the other, discharges through it.

The solenoid is actuated one way or the other by the capacitor charge and discharge pulses.

The pulse width (time constant RC) is determined by the capacitance and the solenoid coil resistance.

Nandu.

 

To deliver a controlled 2 millisecond reversed polarity pulse will require a circuit called an "H-Bridge", and a suitable driver circuit. Quite common but not so simple.

AS in Post #9

 

Certainly the capacitor scheme shown in post #13 will work if that contact functionality is available. As I read the description of the system operation, described by the TS in post #10, it is not clear to me that such functionality is available.