Touch Switch Door Bell Type

Skema Rangkaian Bel Pintu Saklar Sentuh

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Rangkaian Bel Ding dong

Skema Rangkaian bel Rumah

This simple circuit an low cost ding dong bell suitable for calling bell purposes. It is made around IC 8021-2 . IC 8021 has an in-built circuitry to produce ding dong sound each time its pin 3 is pulled low. The sound is stored in a 4 bit ROM.a complementary-pair, two-transistor amplifier is used to amplify the sound to a fair level of audibility. A piezo tweeter or an 8-ohm, 500mW speaker can be used at the output.

List Component bel Rumah:

R1: 1K 1/4W Resistance
C1: 10µF/12-25V Electrolytic Capacitance
T1: BC548/c8050 NPN transistor
T2: BC557/C8550 PNP transistor
IC1: 8021-2 ding dong sound generator
Ls1: Speaker tweeter 500 Mwatt - 5 watt
S1: switch on/off
S2: Switch Normally close
B1: 3V Cell

Each time when switch S2 is pressed, ding dong sound is produced twice. If you try to press switch S2 a second time when the first ding dong sound is still being produed, it has no effect whatever and the two ding-dong bell sounds will be invariably produced.S1 is the ON- OFF switch.Assemble the circuit on a good quality all pupose PCB.Don’t forget to use an IC holder for IC 8021.

IC 8021 Description

The 8021-2 is a ding-dong sound effect generator IC produced by LSI CMOS technology. With built-in RC oscillator and digital envelope circuits, minimal external components are required. This IC simulates the mechanical ding-dong sound, and is ideal for door bell application.

IC 8021 Features
- 1.3V to 3.3V operating voltage and low power consumption
- One-shot mode of 2 ding-dong playing sequences
- Standard TO-92 package form
- Dynamic speaker can be driven with external NPN transistor

IC 8021 Absolute Maximum Ratings
DC Supply Voltage ........................................... -0.3V to +5.0V
Operating Ambient Temperature .................... -10°C to 60°C
Storage Temperature ....................................... -55°C to 125°C

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