3-5-9 VDC Regulated Power Supply

This is an universal power supply with one regulated output, made by me in 1990. The voltage value is selectable by switch from: 3, 5 or 9 VDC. This device uses a LM723 integrated circuit. By using an additional power transistor with heat sink at output and a the current limiter circuit included in LM723, the reliability and thermal stability of the power supply is increased.

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Specification:
- linear regulated power supply
- input voltage: 230 VAC / 50 Hz
- one output with the value selectable by a switch from 3, 5 and 9 VDC
- maximum output current: 200mA
- output protection with current limiter at 240 mA
- medium power NPN transistor BD135 with heat sink on output
- line regulation: typic 0,01%, max 0.1%

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Schematic (PDF)
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PCB Layout

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Links:
[1] - LM723 datasheet