Reading time: 2 minute The project features a tiny amplifier that provides 250mW output and can be used as a final amplifier for radios.
Reading time: <1 minut The presented project is based on the integrated circuit 555. Through the 3 transistors (T1, T2, T3) and the capacitor C2, the circuit "pumps" energy to the battery to be charged. Thus, the energy transferred to the charging battery is sufficient to provide a charging current of about 900mA. The LEDs are added to the circuit to prevent the two transistors from opening at the same time.
Reading time: <1 minut The project aims to learn the operation of a photo-resistor in a circuit with two transistors. This circuit with two transistors (BC337) activates the LED1 indicator when the light falls on LDR1 (Light Detecting Resistance). The POT1 potentiometer is adjusted for the required sensitivity. The supply voltage is 3V.
Reading time: 2 minute Many people do not realize that there are two junctions in the bipolar transistor, and they do not know that the base-emitter has a breakthrough voltage in the catalog, of 5V. Thus, ignition pulses are generated based on two phenomena: break-down voltage and the avalanche effect.
Reading time: 2 minute The presented project generates a sound similar to that of a cricket. It is based on the LM324 integrated circuit. The maximum current consumed by this circuit is 30mA. The LM324 consists of 4 operational amplifiers, but only 3 of them are used for this circuit.
Reading time: <1 minut This project generates sounds similar to those of ambulances. As can be seen, the circuit consists of two stable stages. Thus, the group of components T1, T2, C2, C3, R1, R2, R3, R4 forms a low frequency generating stage and the group of components T4, T5, R7, R10, C5, C6 forms a high frequency stage. The output signal will then be amplified using T6.
Reading time: <1 minut This circuit, as the title suggests, indicates when a fuse is broken. As long as the safety is good, the LED lights up continuously, and when it is interrupted, the LED flashes.
Reading time: 2 minute A rain sensor is a technical component or a technical assembly, which can determine if and how much rain, to give a signal to an action. There are several reasons why the rain sensor is used. In case of precipitation, it can give an impulse to a device (pump) that stops the irrigation; can give an impulse to close a door or a window; can give a signal, when it rains, to a windshield wiper motor, etc.
Reading time: <1 minut The project presented can be used as a rear warning light for bicycles. After pressing the SW1 switch, the LEDs will flash.
Reading time: <1 minut The presented project generates a frequency signal around 1000 Hz. This assembly uses two complementary transistors, ie, one npn (2N2222) and one pnp (2N2907).