Electronic Fuse for DC Short Circuit Protection by BRX46

Description:

This is an electronic fuse that protects the load against short circuit. Relays must be chosen with a voltage value equals to the input voltage. Don't omit using the 100uF capacitor with appropriate voltage value with respect to the input voltage. If you can't provide, you can use C106 instead of BRX46.

You can adjust the current with using 10K potentiometer. If you will use the fuse with very high currents, lower the 0R6 5W resistor value (ex. 0R47, 0R33, 0R22 or 0R1). Watt value of the resistor should be increased also. 

You can download ARES PCB layout file of the circuit from here .

Low Cost 2x20 Watt Stereo Amplifier by TDA2005

Description:  

This circuit is a small stereo amplifier for all suitable applications like amplifying small speakers, boxing, etc. It is also suitable for car use but before, the power supply must be choked with at least 150mH and it must give up to approximately 6 to 7 amps during the upstream performance.

Technical data:
Performance  of TDA2005M: (for this circuit); At 14.4 V supply voltage: 2 x 20 watts (stereo) into 4 Ohms.
Distortion: Approx. 0.2% at 4 Watts into 4 ohm load.
Frequency Range: Approx. 20 Hz to 22 KHz.
Input Sensitivity: Approx. maximum 150 mV rms. .
Power supply: + 8 to 18 volts, approx. maximum 3.5 Amps per channel.

Appropriate heatsink for the amplifier is SK08 with a height of 50 mm  (approx. 2.5 K per watt). You should drill the cooler after soldering the board to center it properly. The TDA2005 also needs not be isolated from the heat sink, since the metal mounting part of the IC is grounded. You should use thermal paste to improve the heat dissipation. After the assembly , case construction is left to the builder. 100K potentiometers are used for adjusting the input volume. The potentiometers are absent in the layout. The 100K resistors need only be installed if the 100 K potentiometers are not used as shown in the layout.

You should use a well designed quality transformer to get less noise. It will be another good way to use a sufficient battery to power the circuit. Keep the supply wires as short as possible. Input source should be isolated from the external noises too. It is recommended to use coaxial cable to connect the input audio.

Click here to download schematic, PCB and layout files.