12V Battery Charger - How do we charge 12V batteries cheaply?

12V Battery Charger - How do we charge 12V batteries cheaply?

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.

Light detector with 2 transistors - How do we detect light with LDR?

Light detector with 2 transistors - How do we detect light with LDR?

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.

What is break-down voltage and avalanche effect?

Electronic fireflies with a single LED - What is the break-down voltage and the avalanche effect?

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.

Ambulance siren with transistors - Transistor sound games

Ambulance siren with transistors - Transistor sound games

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.

Rain Sensor - What is a Rain Sensor?

Rain Sensor - What is a Rain Sensor?

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.