CKRA4820

Solid state relays (SSRs) are an essential part of many modern circuitry designs. They are widely used to control and manage the current, voltage and other electrical signals in various projects. The CKRA4820 is a single-phase solid state relay, designed to switch high-power loads up to 250V and 48A at 25℃. It is also suitable for many applications requiring long cycle switching or fast response.

The CKRA4820 consists of a bi-directional MOSFET switch, two optically isolated control inputs, status LED indicator, a wide operating temperature range and an extensive line impedance range from 0.2Ω up to 40Ω. The CKRA4820 offers fast switch-time and a wide range of power levels (from 1 watt to 400 watts). It is also designed with low power loss and minimal stand-by power.

The CKRA4820 has several applications in various industrial and electronics projects. It can be used as a load switch in automation and works in both logic and analog levels. It is also suitable for AC motor speed control, lighting control, power optimization, remote sensing, power supply sequencing, and motor speed control. It can also be used in data logging systems, in-circuit programming, and micro-controller systems.

The working principle of the CKRA4820 is quite simple. It is a solid-state relay with two optically isolated control inputs. It has an LED to indicate whether or not the relay is on. When the LED is lit, the relay is on and the load is switched. When the LED is off, the relay has been switched off and the load is not switched.

The bistable circuit is used to control the state of the relay. The circuit is internally discrete logic with a driving circuit powering the optical isolator. The driving circuit produces a current that is proportional to the voltage applied to the control inputs. When the control inputs are high, the output of the driving circuit is also high and the optical isolator is turned on. This turns the MOSFET switch on, which then closes the circuit and allows current to flow through the load.

When the control inputs are low, the optical isolator is turned off, which turns the MOSFET switch off. The load is then switched off and the LED indicator turns off. This is the working principle of the CKRA4820 thermal overload relay.

The CKRA4820 is a versatile and highly reliable thermal overload relay. It has a wide operating temperature range and an extensive line impedance range, making it suitable for a variety of applications. The bistable circuit provides reliable and fast switching, while the LED indicator provides a visual indication of the relay status. This provides an efficient and cost-effective way to switch loads of up to 48A and 250V.