Sound bell circuit with ic 8021
Audio diagram
This is a simple bell sound generator circuit,Power supply 3Volt, and used on small speakers,and there is less equipment to create simple, well offline. Operation of the switch S1 is in ON position to a current flowing into pin 5 of IC.To IC1 by IC1 to work with a sound production IC Ting Tong.When we switch S2 will cause the voltage at pin 3 of IC1 is 0 volts, IC1 to function as a result.The output signal from the pin 6 of IC.The signal will be increased by the amplifier Q1 and Q2.This is the audio amplifier. Extending the leg …
Mini intercom circuits using  one OP-Amp IC
Amplifiers
These are two simple mini intercom circuit. They use IC-OP-amp as main parts. 1. LM380 mini intercom circuit It uses IC Op-amp number LM380 just one as a result can work already. When switch S1 stay in a position speaks loud show in circuit picture. The loudspeaker of mother station will perform to is microphone for drive op-amp. By change step up transformer or T1. The switch of child station will must is in a position listens. The voltage of power supply stay in 8-20 volts sections. LM390 MiNi Intercom Today we find many of the IC number LM390 in …
4 Gate Tone Generator Circuits  using  IC-4011
Basic Circuits
Here is the tone generator circuit,it is small size. I use IC digital Cmos 4011 quad NAND gate. Simple Tone Generator Circuit This will cause another NAND gate to pulse oscillator which will drive another gate to output a 1.3KHz tone. The transistor provides drive for the 8 ohm speaker. The IC 4011 ‘s Input pin 1 for Control output tone generator, so logic “Low” don’t have tone but logic “HI” it have tone sound at speaker. The capacitors C1 and C2 are determine tone frequency rate. And the resistors R3 is control sound volume,so it must have less than …