Summary of Adjustable HV Power Supply for Stompbox
This article details a DIY Switch Mode Power Supply (SMPS) based on the NE555 timer, designed to convert low input voltage (5–15 VDC) into high output voltage (92–340 VDC). It is ideal for powering subminiature tubes, Nixie clocks, Xenon lamps, and guitar effects pedals. The module operates at 45kHz with no audible noise and includes specific warnings about RF shielding and filtering for optimal performance.
Parts used in the Adjustable HV Power Supply:
- Prototype PCB 5x7 cm (Single Side Copper)
- Power Inductor Coil 85uH
- 2N2222 Transistor
- MOSFET IRF740 400V
- Fast Rectifier Diode (FRD) 400V
- NE555 Timer IC
- DIP 8 pin IC socket
- Trimpot 10k
- Electrolytic Capacitor 470uF/25V
- Electrolytic Capacitor 2.2uF/400V
- Resistors (6 units as per schematic)
- Disc Capacitors (2 units as per schematic)
- Terminals for PCB (4 units)
This SMPS can be powered with low input voltage, from 5 VDC to 15 VDC.
Adjustable Output Voltage: + 92 Vdc to +340 Vdc
This assembled module of the SMPS can be used as power supply, for guitar pedal booster, effects stompbox,
with subminiature tubes ( CK series, 5702, 5744, 5718, 6112, 6021, 6286, … ). Can be used too, as power supply, for the Xenon Lamp, Nixie tube Clock, VFD display, Magic Eye, Neon, and too many others electronics circuits who need HV power supply to work. Is great to use with many models of Nixie tube. It can drive 6 Nixie tubes, in multiplex mode, from 180 to 200V. Powered with low voltage from 5VDC to 15 VDC. With this SMPS you can power 250V @ current of 7.5mA! *In all case above, important note, DC and AC filters must be improved, if is desired reducing present HF frequency noises at output! Another fact, informed before, the RF energy is irradiated as magnetic and electric field, shielded assembly could be necessary!
The electronic schematic is available on the pictures).
- Input + 5 Vdc to +15 Vdc maximum! 0.5A Max. ( Be sure, do not input power overload ).
- Workable Output Voltage: + 92 Vdc to +340 Vdc .
- Power Input Max.: 7.5W
- Working frequency: 45KHz +/- 15kHz ( varies in function of the load, input and output voltage ).
- No audible noise.
- Weight: 40g
- Dimensions ( W x D x H ): 70 x 50 x 20 mm.
Step 1:
Fun with this DIY, to assemble this simple Switch Mode Power Supply (SMPS).
After assembled, this module of the SMPS can be used as power supply, for battery powered portable tube radios, and amplifiers. Is great to use with subminiature tubes, CK 5072, 5744, 5718, 6112, and other devices who need high DC voltage. This SMPS is based on the classical NE555! ( see schematic on the pictures ).
The suggested PCB layout is to guide with the placement of all parts.
Step 2:
The part list for this DIY kit is composed by:
- 1 x Prototype PCB 5×7 cm ( Single Side Copper) Hole diam. 1mm – Hole pitch: standard 2.54mm
- 1 x Power Inductor Coil 85uH ( shielded and with “GAP”)
- 1 x 2N2222 Transistor
- 1 x MOSFET IRF740 400V
- 1 x Fast Rectifier Diode (FRD) 400V
- 1 x NE555
- 1 x DIP 8 pin IC socket
- 1 x Trimpot 10k
- 2 x Electrolytic Capacitor 470uF/25V and 2.2uF/ 400V
- 6 x Resistors ( see the schematic )
- 2 x Disc Capacitors ( see the schematic )
- 4 x Terminals for PCB
Read more: Adjustable HV Power Supply for Stompbox
- What is the input voltage range for this SMPS?
The device accepts an input voltage from +5 Vdc to +15 Vdc. - Can this power supply drive Nixie tubes?
Yes, it can drive up to 6 Nixie tubes in multiplex mode using 180 to 200V. - Does this circuit produce audible noise during operation?
No, the design ensures there is no audible noise. - How do I reduce high-frequency noise at the output?
You must improve the DC and AC filters if you wish to reduce present HF frequency noises. - Is shielding necessary for this assembly?
Shielding may be necessary because RF energy is irradiated as magnetic and electric fields. - What is the maximum working frequency of the unit?
The working frequency is 45KHz +/- 15kHz, varying based on load and voltage. - What is the maximum current output capability mentioned?
The SMPS can deliver 250V at a current of 7.5mA. - Which integrated circuit is the core component of this design?
The SMPS is based on the classical NE555 timer IC.
