speaker crossover circuit: This speaker crossover circuit is for bass speaker mid speaker and tweeter. we have to use this circuit to protect the speaker and tweeter. if we don’t use this circuit then the tweeter will burn. and the sound also will not be good. every soundbox needs this …

Adjustable power supply:  This is an adjustable power supply. we can adjust the voltage using this circuit. it’s an easy circuit diagram. here use lm317 ic. we can adjust 1.25 voltage to 37 voltage and 1.5 amperes. this circuit is only for DC voltage. transistor circuit diagram of 2sa1943 and …

Capacitor voltage calculation: This is the Capacitor voltage calculation list. we can learn the value code from this photo. ceramic capacitor got only the value code. we have to know the code value. we can see here that this circuit has 2 capacitors. both are different value codes. like 1A …

SMD resistor calculator: This is an SMD resistor calculator. we can calculate the resistor value according to this. every resistor has a color code or number code. here in this picture, we can see. resistor got brown black and red. brown is 1. black is 0 and red is 2. …

Bridge amplifier circuit: This is the Bridge amplifier circuit diagram. it’s a pre-amplifier for the amplifier. every amplifier needs a pre-amplifier. this circuit works as a pre-amplifier. here used 60-0-60 voltage. we can use 15-0-15 voltage to 100-0-100 voltage. for this, we have to change the 4k7 resistor. for 15-0-15 …

Switch on-off using the password: This is a circuit to switch on or off using a password. this circuit is so simple to make. here use 4 rotary switches to make passwords. every switch has 10 outputs. every output can make a different number. we can set every output in …

security light circuit diagram: This is the security light circuit diagram for the office hostel or the factory. every place we can use this circuit to control the lights. they can switch on/off the lights but if the office wants they can’t off the lights. all lights depend on the …

Amplifier circuit using stk4141: This is an Amplifier circuit using stk4141. this is a stereo diagram. we can use a maximum of 24-0-24 voltage on this board. this diagram can make 50+50 watts. this type of circuit makes a musical sound. per channel is 50 watts. this is the circuit …

12 voltage amplifier circuit: This is the 12-voltage amplifier circuit diagram. we can use a 12-volt battery. for this, we can use it in the car. this diagram can make 50 watts+50 watts. we can use 8 volts to 18 volts. this is a stereo diagram. here use 4 tda2003 …

Bass tone circuit : This is the Bass tone circuit board for the audio amplifier. every amplifier needs this circuit. it’s without a preamplifier. it’s only the audio graphic to control the sound quality. we can make the sound as we want.  here, I used 3 volumes. all volumes are …