merrill Posted October 8, 2004 Report Posted October 8, 2004 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? Quote
merrill Posted October 9, 2004 Author Report Posted October 9, 2004 Merrill,Welcome to the forum!Why don Quote
hotwaterwizard Posted October 9, 2004 Report Posted October 9, 2004 How about an easier circuit? Quote
ante Posted October 9, 2004 Report Posted October 9, 2004 Merrill,Try this one; the potentiometer can be adjusted for reliable toggling. You can use 40106, 74LS14 or 74LS132 and many others if you don Quote
merrill Posted October 11, 2004 Author Report Posted October 11, 2004 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.) Quote
hotwaterwizard Posted October 12, 2004 Report Posted October 12, 2004 I found Several Datasheets and More Info on the aqz202http://www.naisweb.com/e/relaye/semi_eng/pdf/semi_eng_use.pdfhttp://www.matsushita.de/home/www/eu/ac/download/datasheet/relay/pmos_1030dlde0301.pdf http://www.aromat.com/pcsd/aqz10_.pdfhttp://www.naisweb.com/e/relaye/semi_eng/pdf/semi_eng_ppr1.pdfhttp://www.naisweb.com/e/relaye/semi_eng/semi_eng_ppr1/ida52mx.htmlhttp://www.naisweb.com/e/relaye/semi_eng/semi_eng_use/p_m_ca002.htmlhttp://www.naisweb.com/e/relaye/semi_eng/semi_eng_ppr1/pow___005.htmlhttp://www.nais-e.com/ Quote
merrill Posted October 12, 2004 Author Report Posted October 12, 2004 The photo mos switch is working very well. The problem is in the 7474 toggleing the way the circuit is configured. It should toggle , but I am overlooking something. Quote
audioguru Posted October 12, 2004 Report Posted October 12, 2004 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. Quote
MP Posted October 12, 2004 Report Posted October 12, 2004 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.**MP Quote
audioguru Posted October 12, 2004 Report Posted October 12, 2004 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:http://www.imagesco.com/articles/piezo/piezo08.html Quote
hotwaterwizard Posted October 12, 2004 Report Posted October 12, 2004 http://www.discovercircuits.com/PDF-FILES/4013oneshots.PDFhttp://www.discovercircuits.com/PDF-FILES/dflip1shots.PDFhttp://www.discovercircuits.com/PDF-FILES/badgfls1.pdf Quote
merrill Posted October 13, 2004 Author Report Posted October 13, 2004 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. Quote
trigger Posted October 13, 2004 Report Posted October 13, 2004 I think you can do some time delay circuit on the reset pin of IC 4013. Just simple RC can do.I have tried a few circuit on 4017 with about the same problem of random and I can eliminate them with such addon.So good luck then. ;D Quote
login
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.