Alarm Circuit. - This is the other electronic design circuit for implementating of NE555 IC in this time for you. This electronic design circuit mentioned with sensitive optical brglar alarm based on NE555 IC as the major component used.
The electronic design circuit of sensitive optical burglar alarm circuit look like shown in Figure 1 below. From the circuit shown, that there many other major component used like transistor, led, resistors, and capacitor.
The electronic design circuit of sensitive optical burglar alarm circuit look like shown in Figure 1 below. From the circuit shown, that there many other major component used like transistor, led, resistors, and capacitor.
Beside we will show you electronic design circuit and component parts need, we also will give you global description about this circuit. So, please enjoy to continue reading this article until finish and get more useful.
Electronic Circuit Design
Component Parts
- R1, R5 = 1 KΩ
- R2 = 100 KΩ
- R3 = 4.7 KΩ
- R4 = 10 KΩ
- VR1 = 1 MΩ
- VR2 = 100 KΩ
- C1 = 1 µF/16V
- C2 = 0.01 µF
- C3 = 0.047 µF
- C4 = 0.01 µF
- C5 = 47 µF/25V
- IC1, IC2 = NE555
- T1 = 2N5777 Photo Transistor
- T2 = BC547
- LED1 = RED LED
- LS1 = 8Ω / 0.5W
Description
The electronic circuit design like in Figure 1 above show you sensitive optical burglar alarm circuit using NE555 IC. Other component need also that can supply with low voltage DC 12V source to charge this IC and all system component. With this electronic design circuit you can produce alarm for security system that useful now.
According ElectronicProjects blog mentioned that this optical burglar alarm uses two 555 timer ICs (IC1 and IC2). Both the ICs are wired as astable multivibrators. The first astable multivibrator built around IC1 produces low frequencies, while the second astable multivibrator built around IC2 produces audio frequencies.
General-purpose Darlington photo-transistor T1 is used as the light sensor. To increase the sensitivity of the circuit, NPN transistor T2 is used.
Place phototransistor T1 where light falls on it continuously. Phototransistor T1 receives light to provide base voltage to transistor T2. As a result, transistor T2 conduct to keep reset pin 4 of IC1 at low level. This disables the first multivibrator (IC1) and hence the second multivibrator (IC2) also remains reset so the alarm (LS1) does not sound.
General-purpose Darlington photo-transistor T1 is used as the light sensor. To increase the sensitivity of the circuit, NPN transistor T2 is used.
Place phototransistor T1 where light falls on it continuously. Phototransistor T1 receives light to provide base voltage to transistor T2. As a result, transistor T2 conduct to keep reset pin 4 of IC1 at low level. This disables the first multivibrator (IC1) and hence the second multivibrator (IC2) also remains reset so the alarm (LS1) does not sound.
