DC-AC / DC-DC ROYER mini converter
This small size module operates from 0.7 V and delivers very high a.c. or d.c. voltages.
(There is a fast rectifier diode on the board)
Dimensions: 21 x 43 x 15mm (H)
Alternative output: from 100VDC ( when input is 0.8V) to more than 1,200VDC ( when input is 4V)
Average power: 2.5W
Output current: from 30 mA to a few mA ( depending on the input and output voltages.)
Continuous voltage: 500 V maximum, with UF4007 diode.
Oscillation frequency: about 50 kHz, frequency and efficiency can be changed or optimized by increasing the value of C1 (33 nF).
Efficiency: 60 to 80% ( depending on load and voltage ratio)
The secondary voltage is separated from the main voltage by removing the strapp near R1.
Higher voltage can be reached by diodes voltage multiplier.
The output voltage can be controlled easily.
Precautions: With a low primary supply voltage (1 or 2 V), the high voltages can be reached when no-load or low load.
Schematic of application example:
In these examples, the value of C is omitted, a few µF capacitor is enough under the appropriate working voltage and oscillation frequency.
Any diode used with this circuit must be fast and withstand at least twice the peak output voltage.
Idea of circuits
Simple zener diode stabilizer, isolate the input and output by removing the strapp.
Transistor and zener diode controller, transistor is any NPN: bc237, 2n2222, etc.
There is no way to isolate the input and output, must keep the strapp.
Regulation with input-output isolation by opto-coupler, use 6N139 or similar.
Double outputs + and -, it's better to use the diode uf4007 (fast version of the 1N4007)