buzzer circuits

I tried to fix a buzzer circuit with reset capabilities to a machine or<br>handler. The buzzer circuit system well is activated when there is an<br>error message in the machine and the user able to reset the alarm.<br>Currently, I tried to tap the signal or supply for the circuit from the<br>tower light. When there is an error message the red light well is<br>activated so, I connected the circuit in parallel with the red light<br>supply.<br>Whereby, the supply will be 24v when red light is activated. FYI, the<br>light is triggered by ground signal not by supply.<br><br>Aboveentioned buzzer circuit compromise of following circuit<br><br>1. Since the circuit works with 12v so we used a regulator circuit.<br><br>2. Followed by 555 press to turn off circuit.<br><br>3. buzzer was connected at the output of the circuit<br><br>12v regulator cct-----555 IC Press ---------buzzer<br>off circuit(reset)<br><br>However, when I connected it cause the controller board in the computer<br>malfunction or

 

[Tedjo]

Dear sir,<br><br>The output as you said that connected to a buzzer. Unfortunately I can't read your complete letter. Anyway in my experience; replace the buzzer with a small 12VDC relay (if your final driver strong enough to drive both buzzer & relay connect it together -in paralel). Then the relay contacts could be wired in series with the light bulb into your 24VDC supply. The relay will interface the light bulb to the main 555's circuit.<br>Good luck!

 

[ProductDesigner]

What is the controller output driver. If we knew, we can estimate its capacity.<br><br>555 timers can produce large pulse demands on the supply during output transition.<br><br>The relay idea is good. It buffers the controller output.<br><br>Don't forget to suppress the relay coil. The controller may not have that capability.<br><br>Let me know.