KicadJE-EuroPowerSupply2

4HP PSU faceplate with 80x100mm PSU + PDU board. Faceplate input from a laptop PSU (19V) and may be daisychained to the next Eurorack unit.

Please note this method of making +- 12v could be impaired by the laptop PSU ground connection. Some PSU's connect earth to GND (sleeve) which will be connected to -12v and not GND in this circuit. If the laptop PSU only has 2 pins or the 3rd pin is not connected to the sleeve of 19v supply there will be no issues with this design.

There is a third version that does not rely on a laptop supply in the making (2025 Q1)

Vital Components

Status - mounted in rack

Initial

Stage	Detail	Status
create material	sch	done
	pcb	done
	gerber	done
production		done
	produced	done
	delivered	done

Preliminary validation

Test	Detail	Status
Initial Inspection		good alignment w panel - panel: pwr holes 2 mm too small
Initial Technical Test		OL LED's lighting up without load - probably due to the extra resistance of the polyfuse
Initial Technical Test		OL LED's ok with 2k2 but unsure of how they work now - 3k9 is ok without load but makes a bit of a light at a few XX mA
Initial Technical Test		input fuse experienced a few problems after shoring the input of the DC-DC by mistake
Initial Product Test		ok - Powers the uP DAC nicely

Secondary validation

Test	Detail	Status
Product Test
Product Test
Quality
Quality
Long Term Product Test		Working for a year without stability issues
		Bridge recitifier gets warm/hot
Power Draw	up to 750mA 19V

Errata

Errata -

Holes for Pwr in and out are 2mm too small in face plate

Place DCDC input further away from electronics on the backside - risky location

Issues and Notes

Front

There is just enough room on the front PCB to add a JST header for power feed to baseboard.

Regulation

Input cap C101 = 470uF/50V

Reg input cap C207 - 470uF/16V for 5V

Reg input cap C204 C212 - 100uF/35V for +-12V

Reg output cap C206 C209 C214 - 470uF/16V for all

Output

Only half the headers has decoupling caps

Place +/-15v header away from heatsink area.

Overload Circuit

Not easy to measure the OL circuit as it is VERY close to the DC-DC input
Add current limiter on input and consider changing from OL to currentlimier with limit indication
OL LED's ok with 2k2 but unsure of how they work now - 3k9 is ok without load but makes a bit of a light at a few XX mA

Extensions

Consider calc initial regulator stage as Capacitor multiplier and add small signal BJT in darlington config.

• https://www.google.com/search?q=eeblog+david+jones+capacitor+multiplier&oq=eeblog+david+jones+capacitor+mul&aqs=chrome.1.69i57j33.18679j1j7&sourceid=chrome&ie=UTF-8

Pictures

Rendered

Schematic

Prototype

Inspiration

Rev 1

https://github.com/promesoft/KicadJE-EuroPowerSupply