The important part of the circuit is formed of the Colpitts type oscillator. C3,C4,C5,C6,CD1-CD2 and L1 determines the frequency. BF982 and dual gate MOSFET are active parts in oscillator. When the input impedance of the MOSFET gate inputs are high, LC tank is not affected. However transistors force the LC tank and cause phase shift. [...]
R1, R101 56 kOhm C1, C101 47 µF/6,3 V, elektrolyt.R2, R11, R102, R111, R16 12kOhm C2, C102 100 nF, fóliovýR3, R103 22 kOhm [...]
Circuit power supply 5V 5A by 7805+Mj2955
This is circuit 7805+Mj2955 power supply 5V 5A for digital circuit.Q MJ2955 for to increase form IC 7805. Q A16 for overload protect.
This is a classic signal mixer that is used for audio purpose. VR1 & VR2 are inputs audio volume controlers and VR3 is used to control the balance between Input1 and Input2. connect a dynamic microphone to Input1 and a music without vocal to Input2, then adjust the VR1, VR2 and VR3 for obtaining a [...]
AVR Thermometer TCN75This small thermometer board uses the Microchip TCN75 device. It is a cheaper clone of the LM75, it costs about 2,50 Euro. The TCN75 comes in a SO8 packaging. The TCN75 is a serially programmable temperature sensor. It has an output that is programmable as either a simple comparator for thermostat operation or [...]
This RF Amplifier is used for boosting small fm transmiters and bugs. It use two Philips 2N4427 and its power is about 1Watt. At the output you can drive any linear with BGY133 or BLY87 and so on. Its power supply has to give 500mA current at 12 Volts. More voltage can boost the distance [...]
Portable iPod charger that you can use while away from your computer. The circuit is based around an MC34063 switchmode regulator. This has high efficiency so that there is very little heat produced inside the box, even when delivering its maximum output current. The circuit is more complicated than if we used a 7805 3-terminal [...]
40W Amplifier by 2N3055+MJ2955The 40W Amp OCL 2N3055+MJ2955 is easy to build,and very inexpensive. To use Power Supply +35V -35V >2A.Transistor 2N3055+MJ2955 must be mounted on heatsink.Can be directly connected to CD players, tuners and tape recorders.
Parts:R1, R2, R5, R6 22 kOhm (SMD 1206)R3, R4 2,2 kOhm (SMD 1206)R7, R8 4,7 Ohm (SMD 1206)P1 4,7 kOhm, potenciometr logaritmický stereo RadiohmC1, C2, C7, C8, C9 100 nF (SMD 1206)C3, C4 100 µF/10 VC5, C6 470 µF/10 VC10 47 µF/16 VIO TDA2822M
This project allows instant start sequentially but a dozen low-voltage lamps 12 V / 60 W, and makes them fade and always sequentially (but slower). This system has been designed to meet the demand of a visitor who wanted ten recessed low voltage spot in a driveway to his house, with the following function: – [...]
This circuit allows switching on a LED when the battery voltage (12V) drops below a certain threshold. The operating system is based on a comparison of tension, which comes in a zener diode. If the supply voltage is 12V and the zener diode is a 10V model (this is the case in the diagram), we [...]
This is a good looking and practical device that can be useful in many areas where countdown timer is needed. This project is based on the PIC16F84A microcontroller. The time range can be adjusted between 1 and 999 seconds. This project has 3 buttons and one of them is named Set Button. In order to [...]
A VU meter is often included in audio equipment to display a signal level in Volume Units; the device is sometimes also called volume indicator (VI). In this project we are building a basic and low cost LED VU Metre circuit . The extent (range) display is -18 dBu to +3 dBu, spread over [...]
Today we have a new category “Projects” and a new electronic project 12 Channel LED Chaser with PIC16F84A.
This project is based on the popular PIC16f84A micro-controller.The heart of this project LED chaser is the PIC16F84A PIC microcontroller.A 4MHz crystal and capacitors C1 and C2 22pf is used for providing clock pulses to the micro-controller. The [...]
