Water limit buzzer

Simple Buzzer driver with 555

This very simple circuit just uses a couple of resistors, a capacitor and the easily available 555 timer IC. The 555 is setup as an astable multivibrator operating at a frequency of about 1kHz that produces a shrill noise when switched on. The frequency can be changed by varying the 10K resistor.

LOUD PIEZO ALARM BEEPER

This is yet another beeper circuit that really draws attention. It sweeps the drive frequency slightly to produce a very annoying sound. It uses a transformer to increase the drive voltage across the piezoelectric device to more than 200 volts peak to peak. It cranks out an ear splitting 120db...

Door Chime Schematic

No Description available.

Cmos Piezo Driver Circuit

A CMOS-gate and transistor buffer can be used as an effective driver

POWER REMINDER BEEPER

This circuit produces a short beep once each minute. It is powered directly off the 120vac power line to remind you that a device connected to the circuit is turned on. It is simple enough to be packaged inside a small plastic box. It might be ideal for computers, printers or some test equipment...

Piezo Driver Circuit

Using a PA41 from Apex Microtechnology, this monolithic amplifier is capable of 350-V operation

Two tone generation

No Description Available.

BASEMENT DOORBELL BEEPER

If you can`t hear your doorbell when you are in your basement try this circuit. This circuit takes advantage of the 24vac power source located near the furnace. Using a simple current transformer technique, the circuit sounds a beeper whenever the main door chime is activated.