Summary of PIC Controlled Relay Driver using pic microcontoller
This article describes a PIC Controlled Relay Driver circuit based on the PIC16F84A microcontroller, capable of controlling four separate electrical devices via relays. The design includes noise reduction features such as a 1:1 line filter transformer for industrial use. The power supply is carefully engineered with transformers, voltage regulators, fuses, and varistors to ensure stable operation and protection against electrical noise and surges.
Parts used in the PIC Controlled Relay Driver:
- PIC16F84A Microcontroller
- 220V/12V 3.6VA PCB Type Transformer (EI 38/13.6)
- Line Filter (2x10mH 1:1 Transformer)
- 12V Relay (SPDT Type) - 4 pcs
- BC141 NPN Transistor - 4 pcs
- 2 Terminal PCB Terminal Block - 5 pcs
- 1N4007 Diode - 4 pcs
- 250V Varistor (20mm Diameter)
- PCB Fuse Holder
- 400mA Fuse
- 100nF/630V Unpolarized Capacitor - 2 pcs
- 220uF/25V Electrolytic Capacitor
- 47uF/16V Electrolytic Capacitor
- 10uF/16V Electrolytic Capacitor
- 330nF/63V Unpolarized Capacitor - 2 pcs
- 100nF/63V Unpolarized Capacitor
- 4MHz Crystal Oscillator
- 22pF Capacitor - 2 pcs
- 18 Pin 2 Way IC Socket
- 820 Ohm 1/4W Resistor - 4 pcs
- 1K 1/4W Resistor
- 4.7K 1/4W Resistor
- 7805 Voltage Regulator (TO220)
- 7812 Voltage Regulator (TO220)
- 1A Bridge Diode
We love to read emails from our visitors, Please let us know by clicking here if you find any kind of bug/error in our site. We will fix it as soon as possible. PIC Controlled Relay Driver This circuit is a relay driver that is based on a PIC16F84A microcontroller. The board includes four relays so this lets us to control four distinct electrical devices. The controlled device may be a heater, a lamp, a computer or a motor. To use this board in the industrial area, the supply part is designed more attentively. To minimize the effects of the ac line noises, a 1:1 line filter transformer is used.
The components are listed below.
1 x PIC16F84A Microcontroller
1 x 220V/12V 3.6VA (or 3.2VA) PCB Type Transformer (EI 38/13.6)
1 x Line Filter (2x10mH 1:1 Transformer)
4 x 12V Relay (SPDT Type)
4 x BC141 NPN Transistor
5 x 2 Terminal PCB Terminal Block
4 x 1N4007 Diode
1 x 250V Varistor (20mm Diameter)
1 x PCB Fuse Holder
1 x 400mA Fuse
2 x 100nF/630V Unpolarized Capacitor
1 x 220uF/25V Electrolytic Capacitor
1 x 47uF/16V Electrolytic Capacitor
1 x 10uF/16V Electrolytic Capacitor
2 x 330nF/63V Unpolarized Capacitor
1 x 100nF/63V Unpolarized Capacitor
1 x 4MHz Crystal Oscillator
2 x 22pF Capacitor
1 x 18 Pin 2 Way IC Socket
4 x 820 Ohm 1/4W Resistor
1 x 1K 1/4W Resistor
1 x 4.7K 1/4W Resistor
1 x 7805 Voltage Regulator (TO220)
1 x 7812 Voltage Regulator (TO220)
1 x 1A Bridge Diode
The transformer is a 220V to 12V, 50Hz and 3.6VA PCB type transformer. The model seen in the photo is HRDiemen E3814056. Since it is encapsulated, the transformer is isolated from the external effects. A 250V 400mA glass fuse is used to protect the circuit from damage due to excessive current. A high power device which is connected to the same line may form unwanted high amplitude signals while turning on and off. To bypass this signal effects, a variable resistor (varistor) which has a 20mm diameter is paralelly connected to the input.
For more detail: PIC Controlled Relay Driver
