Trigger a microwave "Beep" sound

Thread Starter

ThomCircuit

Joined Feb 4, 2020
45
Hi and thank you.
I've got a latching touch sensor component that triggers a relay which turns on some lights. The sensors trigger is 5v. I've connected the sensor to a decorative metal plate via a copper wire. I've drilled a 5mm hole in the plate and inserted a dual blue/red led. The led is always illuminated until the plate is touched changing the color to blue. I used an NGATE to work out that logic. My final task is to make it "beep" each time it is pressed. Browsing this forum I ran across this edge decter circuit. I need a bit of help adapting this to my project. It only needs to produce the beep. I have identified all the components except for the type of speaker. Active,passive,magnetic? I just can't figure that out.
I should mention that I knew nothing about circuits until 4 weeks ago so please excuse my lingo. I hope I've provided enough info. Thank you.
 

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SamR

Joined Mar 19, 2019
2,574
Passive speakers require a frequency input to make sound while active only require voltage and generate their own frequency.
 

Thread Starter

ThomCircuit

Joined Feb 4, 2020
45
Passive speakers require a frequency input to make sound while active only require voltage and generate their own frequency.
Can you tell me what type of speaker is in this circuit? From what I read it appears to be active. I am not familiar with what a passive piezo sounds like does it make a beep sound like that in a microwave oven or is more of a mechanical sound
 

SamR

Joined Mar 19, 2019
2,574
Passive will not make noise unless you supply it with one. To generate sound with simple ON/OFF voltage you want an active speaker that generates its own sound frequency. Different manufactured active speakers will make different sounds. Typically a monotone buzzer sound of different tonal frequencies from very high to very low. The "Ting" bell-like sound of a microwave is probably generated by a sound chip and played to a passive speaker. The keyword on the schematic is Annunciator which is an active speaker/buzzer.
 

cmartinez

Joined Jan 17, 2007
7,083
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