Single-chip mains supply
Single-chip mains supply: Harris’s Type HV-2405E IC, connected with a few external components as shown in the diagram, enables the direct derivation of a regulated 5-24 V d.c. supply from a 100-260 V a.c. mains supply. The peak output current of the device is 500 mA.
The chip contains a pre-regulator that arranges the charging of C. a fairly large capacitance, at the onset of each period of the mains voltage: The charging continues until the potential across the capacitor has reached A level that is roughly the wanted output plus 6 The chip contains a pre-regulator that arranges the charging of C. a fairly large capacitance, at the onset of each period of the mains voltage: The charging continues until the potential across the capacitor has reached A level that i§ roughly the wanted output plus 6 V.
When that state is reached. C2 provides the voltage necessary for the series regulator also contained in the IC. The output of this regulator can be set between 5 V and 24 V with P1 and is available at pin 6.
WARNING. Since the circuit and its output is connected electrically to the mains, any apparatus connected to the circuit is, therefore, also at mains potential. Great care should thus be ever cised when working- on it: touching certain parts is potentially lethal!
The HV-2405E is a single-chip offline power supply that converts worldwide AC line voltages to a regulated DC voltage. The output voltage is adjustable from 5VDC to 24VDC with an output current of up to 50mA. The HV-2405E can operate from input voltages between 15Vrms and 275Vrms as well as input frequencies between 47Hz to 200Hz (see Table 1 in the section titled “Minimum Input Voltage vs Output Current” for details).
The wide input voltage range makes the HV-2405E an excellent choice for use in equipment that is required to operate from either 240V or 120V. Unlike competitive AC-DC convertors, the HV-2405E can use the same external components for operation from either voltage.