This is a simple train whistle circuit. We have many ways to generate a two-tone sound circuit. I love to collect a basic or small circuit. This circuit may be…
These circuits are Simple Metronome circuit model to be simple. It use the transistor be important equipment by very the circuit is the character Astable Multi vibrator. For produce something…
This is simple Warble tone generator circuit , use scr as main of oscillator and signal will be boost, then feedback to SCR again. Output is 32 ohms speaker [....]
When the temperature rise exceeds the limit, it will sound the siren rang out.
Simple Refrigerator Door Alarm circuit
This is a Simple Refrigerator Door Alarm circuit, it will detect light of lamp in the fridge and alert with buzzer.Small size, easy to make and cheapest. [...]
This is Morning sun alarm circuit using IC-4011 that hobby It will have sound alarm when morning like a normal clock alarm with lighting sensor same clock.
The 2 tone doorbell circuit, which is an electronic buzzer types,but them has melodic sound than general electric bell. People have seen two tone bell sound