Making Illuminated momentary push button act like toggle

Discussion in 'General Electronics Chat' started by diebog, Jun 11, 2016.

  1. diebog

    Thread Starter Active Member

    Mar 23, 2013
    I bought these illuminated push button switches from Digikey that I need a few suggestions on which way to go to make them act like a simple on off switch. Press once and its on, press again and its off. I have 2 of these buttons that are replacing standard toggle switches, one provides a ground to a laser's power supply (which turns the laser on) and the other sends a ground signal to an OMRON Sysmac Automation Platform CMP2AH-60CDR-A which enables the Back/Forth movement (on this large Bridge Saw I am working on). It doesn't physically move the bridge back and forth, its more like a safety. Until this OMRON Sysmac sees a constant ground signal on this specific terminal, the bridge can't move back or forward even when the button to do so is pressed. Some specs

    With the laser's supply drawing .25A at 215v and a ground signal for the OMRON drawing ? Is there an simple non complicated way to do this? Ive read about using a 555ic, transistors, flipflops and more, but I would like to keep this a small and simple as possible. In my searches I found this which I think maybe what would work for me, but I don't know. That's why I am asking for help. Which chip do I go with? Would I need a relay which is controlled by one of these IC's suggested? How do I then power the led in the button?

    I know some will say "just go buy a latching push button switch and be done with it." Thing is I am going for the symbol that lights up via an internal led which needs 3.5v or so to illuminate.

    I first thought of going with what I knew and using just plane ole relays as shown here but that isn't really the way I want to go.

    Inside the panel where these are mounted I have a 24vdc that I will use to supply power. Use a LM713 or something to drop it to whatever is needed. Surface mount or though hole is fine. Any suggestion's, idea's are welcome.
  2. Tonyr1084

    Well-Known Member

    Sep 24, 2015
    I was thinking of a Remote Control Circuit Breaker (RCCB) rated at 240 VAC and 30 A.

    However, I don't know HOW they are controlled. Perhaps a push button will toggle them on and off; maybe it takes a SPDT switch (has three wires); or maybe it's controlled by a PCM (Programmable Control Module). Otherwise my first thought to this was a D Type Flip Flop. Simple enough to set up as a clocked switch that turns on (if the last state was off) and back again with the next clock pulse. Certainly cheaper than the RCCB. BUT the problem: How much amperage are you trying to control, at what voltage and how possible is it someone could be at the wrong place at the wrong time when the operator hits the button? If you're talking about a bridge saw then you REALLY need to be concerned with safety regulations. Simply bodging together a circuit in your basement for use on machinery that can potentially take a life - I'd say OSHA is going to want to KNOW your circuit will be 100% reliable in the most extreme conditions. If it fails - what mode does it fail in? Can it accidentally start on its own without input from an operator? Can it reliably shut it down in the case of an emergency?

    If you're looking for liability - I think you may have found it.
  3. crutschow


    Mar 14, 2008
    Here's a circuit I came up with to give bistable control with one or more buttons and LED indication of the ON state.
    The second version shown uses just one wire plus common to the switch for both control and LED illumination.
    Don't know if that's exactly what you want but it might give you some ideas.
  4. diebog

    Thread Starter Active Member

    Mar 23, 2013

    Well there is no real danger and OSHA isn't ever involved because I am self employed and Im in a residential area. But I appreciate your concern. Im not disabling a safety feature, I am just replacing a switch that was already in place with an illuminated push button. As far as draw goes, I posted the info on the laser power supply which is .25A. All the switch did before is provide a ground for the power supply. Cut the ground and no more laser. Simple. So theres no need for a huge breaker type setup. Were talking mA here. And the second button/switch was also providing a ground signal which I have not measured, but the wire being 18AWG and 50' long, It is so minimal I don't even worry about the rating. The entire controls are around water so none of the commands have power to them. The only thing with power is what powers up 1 display. The whole system works off of ground inputs to the main computer/controler (the OMORON). Its a super easy system to understand. You want something to move, you just apply ground to the input terminal on this controller, and the output will control a relay.

    Here is a pic of the saw to help you get an idea what it looks like. The worst that can happen is you bend a blade because the system thinks the motor is raised up. [​IMG]
  5. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    Here's one option, assuming the grounding requirement is for DC :-
    This would need a 12V (not critical) supply derived from your 24V supply.
    Half of the IC provides switch-debouncing, the other half does the toggling.
    The FET should be selected depending on the current it needs to sink and on the pull-up voltage which the power supply or controller provides. If the FET is to switch a relay or other inductive load, then a spike-suppression diode on its drain would be needed.
    Last edited: Jun 12, 2016
  6. diebog

    Thread Starter Active Member

    Mar 23, 2013
  7. diebog

    Thread Starter Active Member

    Mar 23, 2013
    Anyone have any experiences with any of these chips?
  8. KeepItSimpleStupid

    Distinguished Member

    Mar 4, 2014