Building a circuit that involves solid state ralays and 555 timer.

Hello guys!

I am trying to build a circuit and had been thinking about it for a few days but came out with no solutions. I am trying to build a circuit of which when a button is pushed, the 555 timer which is to be configured as a one shot multivibrator will send out an output for 3 seconds. This output will then be sent into a solid state relay which then will close the internal switch. An 18 V supply will then flow through the closed circuit to power the solenoid until after 3 seconds. After three seconds, the one shot multivibrator will go back to its low output state.

I've tried simulating it in MultiSim but the results I got are very erratic. I'm not sure if its my fault or just the simulations fault.

Details of the circuits that I intend to use is as follows though if you guys think it should be modified by all means you can tell me that.
Supply voltage to 555 timer: 9V battery voltage regulated to 5V
Supply to solenoid: 18V (2 9V batteries connected in series)
Voltage regulator: National Semiconductor LM7805CT
555 timer model: National Semiconductor LM555CN
Solid state relay: Vishay Semiconductor LH1500AT

I am intending to use a microswitch for the timer's trigger input.

I am not sure if I should use solid state regulators ot the normal relays. I've heard that solid state relays are more reliable. Please advice me on that too.

I can provide the MultiSim drawing that I did if requested. I really appreciate the help given.

With regards,
Aman.

Any reason you couldn't use the 555 to "control" an N channel MOSFET on the low side of the solenoid?

what do u mean by that? sorry i am not that very educated in this circuits actually.

Instead of the 555 going to a SSR (solid state relay) which in turn would power the solenoid, connect the output of the 555 to a MOSFET which can be used as a switch to control the solenoid.

indulis said:

Instead of the 555 going to a SSR (solid state relay) which in turn would power the solenoid, connect the output of the 555 to a MOSFET which can be used as a switch to control the solenoid.

Click to expand...

by MOSFET you meant transistors? when i simulate in MultiSim, when my timer is output low, i get 2.667V. is it normal? if i use a transistor it will automatically be switched on because of the 2.667V flowing in rite?

You need a better simulator, like LTSpice

Here is how I would drive your solenoid.

MikeMl said:

You need a better simulator, like LTSpice

Here is how I would drive your solenoid.

Click to expand...

THIS IS AMAZING! but wat if i use solid state relays?