Network part conversion 16-24V 15-28V (variable)
The power supply of the brand "ednet.", model "AD-75WXX-XXX" is as described in the output voltage range 16-24V on 15-28V expand.
The resistor R1 is increased by 2 k 7 ohm to 3 k 3 ohms - this sets the lower voltage limit. If the power supply is not start, is the resistance value to shrink (3 k 2, 3 k 1). The variable output voltage setting is carried out via the feed-in point of feedback (see picture) or at pin 2 of the IC FR103. Here, a potentiometer (100 k) in series with a resistor R2 with 2 k 7 Ohms to ground (GND) is switched. R2 sets the maximum output voltage and is measured so that the power supply maximum output voltage does not switch off. (Under certain circumstances, R2 is to enlarge) The wires of the potentiometer are as short as possible, under certain circumstances it is necessary capacitive with 10-100nF directly on the potentiometer to bridges. The now unneeded "sense" line of the output side connection cable can be separated from the circuit board.
On the basis of the performance data, the following performance diagram is as follows:
The ICs in the circuit are "NCP1203-D" as well as "FP103".
CAUTION! I take no responsibility for the accuracy of this information and no liability for damage to property and personal injuries of all kinds. It should be serviced always a sufficient time until the primary charging capacitor to a safe voltage level is unloaded. This is to check if in doubt. Furthermore, it is not uncommon that heat sink/heat sinks in switching power supplies are high potential. The direct contact to the 230 Volt mains voltage can be lethal! AC voltages over 50 volts and DC voltages of 120 volts are life-threatening for people!