This project originally started off earlier last year when I decided to make a single rail power supply. I wanted something I could use to create standalone external power supplies for use with powering headphone amps and DACs to improve the listening experience.
After the release of the Helios Bi-Polar PSUs I decided it was time to revisit the single rail iteration and see how I could improve upon it. The main aim this time was to make it as small and compact as possible whilst still utilising through hole components. I have also retained the 78xx regulator pin configuration as this is quite popular in the audio community. Below is a summary of the changes and improvements I have made:
- Added connector blocks to easily connect input and output without soldering.
- Added onboard fuse as extra level of protection.
- Reduced PCB size to 140mm x 65mm.
- Increased output smoothing cap to 1000uF.
- Made input voltage selection simpler.
- Changed the 4 individual rectifier diodes for a single 4P DIP IC package.
- Moved the External LED connector pads to a more convenient location.
Setting The Input Voltage
To set the input voltage of the board for your country, you must bridge the following jumpers ONLY:
For 220v mains input: Bridge J4 and J5.
For 110v mains input: Bridge J3 and J4 and also J2 and J5.
WARNING!!!
NEVER EVER bridge J2 and J3 as this will cause a dead short and may result in death or injury of which I am in NO WAY responsible or liable.
Bill of Materials
The following components can be ordered from DigiKey:
732-11373-ND x1 F1 Wurth (FUSEHOLDER BLOCKS – PCB – CLIP C)
F 4607-ND x1 Fuse Littelfuse Inc. (500mA Slow Blow Ceramic 5mm x 20mm)
DF04M-ND x1 D1 ON Semi. (BRIDGE RECT 1P 400V 1.5A 4DIP)
399-5464-ND x1 C1 Kemet R46KN 322000M1M 0.22uf/250V Snubber Capacitor (X2 Rated Polypropylene)
493-1883-ND x3 C2,3,4 Nichicon (UPW) UPW1V332MHD 3300uf/35v 20% Capacitor
1N4004-TPMSCT-ND x1 D2 Micro Commercial Co 1N 4004-TP Rectifier Diode 400v/1A
5.1ZCT-ND x2 R1,2 Yageo FMP200JR-52-5R1 5.1 ohm 2W 5% Resistor
HS352-ND x1 HS1 Aavid 531102B 02500G Black Extruded Radial Fin Heatsinks
516-1792-1-ND x1 D3 Broadcom HLMP -1790-A 0002 3mm / 2.3mcd / 1.9v / 2mA Green LED
493-1831-ND x1 C5 Nichicon (UPW Series CAP ALUM 1000UF 20% 25V RADIAL)
102-6161-ND x3 J1,9,10 CUI Devices (2 POS. TERMINAL BLOCK, SCREW TYPE, 5.00)
MC78xxCTGOS-ND x1 U1 ON Semi. MC78xxCTG 78xx Positive Regulator
(Replace xx with the required regulator voltage. Example: 24v – 7824, 15v – 7815, 5v – 7805)
Any one of these transformers:
TE 2261-ND x1 TR1 Amgis L 01 -6365 25VA/22v Transformer (568mA per output)
1295-1079-ND x1 TR1 Talema 70065K 25VA/22v Transformer (568mA per output)
(If you require a lower final output voltage then please select a transformer with a lower secondary output voltage to keep heat dissipation through the regulator to a minimum).
Board Availability
Drop an email to contact@audiosy.net if you are interested in obtaining one or more boards for your use.
Disclaimer:
The boards are provided as is without warranty of any kind. They are intended solely for personal use and are supplied as a bare board only which is classed as an unfinished product. While every effort has been made to ensure the board has been designed with industry standards in mind, it may not depict an exact representation of these standards and as such there may be minor inconsistencies or oversights in the design process. While these boards have been extensively tested, there can be no guarantees whatsoever that the board is completely free of defects and as such caution and due diligence should be taken at all times when assembling and using the board.
Once again thank you to everyone for your support and stay safe!
