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solid state toggle switch

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I am trying to make a solid state toggle switch using a piezo momentary push button switch in connection with a flip flop. I have tried a7474 flip flop circuit without sucess. I want the out put of the 7474 to be on at power up and toggle it on or off with the piezo switch. If this would work it would be a toggle switch that would last indefinetly. If any body thinks they have any ideas I could email you my circuit. I have tried a 4013 with good success for switching but the output comes on randomly at power up. I need it to be on always at power up. Any body have an idea?

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Thanks for the input. A primary design feature for this toggle switch is it use the photo mos switch in the output as shown in the schematic, and a piezo momentary switch in the input side. The 7474 IC or one that will work is important because it needs to take up minimum space. (No moving parts and small! No mechanical relays allowed.)

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I found Several Datasheets and More Info on the aqz202

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Hi Merrill,
What is a piezo switch? If you tap on a piezo, it produces a high voltage that can damage an IC's input.

Ante's 4093 circuit is small and simple and will toggle well. It will be on at power up. It can drive the resistor/transistor that drives your opto.

The capacitors are backwards at your regulator. The big one should be at the rectifier (regulator's input) and the smaller one at the regulator's output.

The LED in your opto doesn't have a current-limiting resistor.

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Piezo switch is a bounceless type of switch with no moving parts. Here is an excerpt from one of the manufacturers of this switch type:

**Unlike an electromechanical switch that has moving contacts and other parts that will eventually wear out, as well as suffer the life shortening effects of pitting, corrosion, contact bounce, and contamination, piezo switches offer many advantages. Piezo switches have no moving parts, are waterproof and impervious to other types of contamination (like coffee, glue, solder flux, detergents, cleaning solvents and others), and are unaffected by EMI or RFI. This results in a switch that has a life expectancy in excess of 50 million cycles.**


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Hi Merrill,
Please post a link to the datasheet for your piezo switch.
Some manufacturers call it a proximity switch.
Another link explains that its output pulse rise and fall times are too slow to directly trigger a 4013 flip-flop! Maybe that is your problem. They cure it by adding a 4050 buffer to its output which speeds-up its transitions. The link (see figure 15) is here:

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Thanks for your input. It is absolutly necessary that the AQZ202 relay turn on at power up. The 4013 circuit will toggle the relay, but the relay is on randomly at power up. I have been told the 7474 circuit would guarantee the relay would turn on at power up. This is what I am trying to accomplish. Yes it does turn on at power up, but it won't toggle. No luck yet. The piezo switch is made by ITTCANNON. It is a very durable switch.

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