The Multipurpose, Universal Power Supply

Requirements

1. 100/200 DC amp output, 120/240AC volt module, 2.4kW - 4.8kW
1. 20A AC in at 120 or 240 V
2. 1DC in
3. At 240V, can output 4.8kW, so needs 200A at output assuming welder voltages
2. Uses Universal Controller for the controller part
• Reads voltage at output
• Provides transistor signals, drives gates directly
• Using the LCD screen, we can select between light dimmer, welder, charger, cordless welder, and motor power supply
• Charger software includes both 18650 packs at 6s, and 12 or 24 v lead acid batteries.
3. Power hardware circuit has terminals for connecting AC or DC power as the input
• DC is from battery pack (no rectifier needed)
• AC is from wall outlet (rectifier is needed with heatsink as needed)
4. Stackability is required
5. Circuit design required in KiCad
6. Board for mounting components is 3D printed with corresponding mounting holes, and integrated open source 3D printed terminals with set screws for ga 6 copper wire
7. Welder handles 3/32” 6011 electrodes

3/32” 6011

The Multipurpose, Universal Power Supply

AC in

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DC in

6 AWG wire, 95A max for single core

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DC out

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Signal Input - ideally, one signal split into 4. May need multiple Arduino pins. Ideally direct drive of transistors, no gate drivers needed.

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V_out measurement

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Termionals for 6 ga copper

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Power Supply operates either on AC or DC input

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50A transistor modules, 1kW each. Cooling Fans if required

Arduino

Minimum Viable Product

What do we need to deliver?

1. One Power Board like on Page 2 - 3 hours of design, 3 hours prototype
1. Modular design
2. Stackable batteries - 3 hours finding a printable battery holder, and print it, and modify it to stack in parallel
1. Configuration of stacking is adjustable
2. DC welder - controlled voltage doing a useful function with SM control. 24V in parallel.
3. AC light dimmer - shows principle of SMPS
4. Battery Charger - transformer

Cordless Welder: Board Stackability - Requirement 2

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DC out

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DC out

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Requirements - Stackability

• The Arduino on the Universal Controller can trigger multiple power boards
• Multiple power boards can be plugged into multiple power outlets or a larger power outlet.
• Output DC terminals must be large enough to fit multiple wires as needed

Arduino

Power Board

200A

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Power Board

200A

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See Simple Electrode Holder

PWM Electric Motor Power Supply

Aka noisy Universal DC Power Supply for Welders, Motors, etc.

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Requirements

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• Uses full wave rectifier for 120 DC
• Target voltage is 24VDC
• Arduino code for Atmel 328 microcontroller is required
• From there, uses PWM driven by Atmel 328 microcontroller etched on previous day
• Uses MOSFETs or IGBTs for the PWM.
• Use power elements that don’t require drivers for circuit simplicity
• Circuit design for power stage is required in KiCad
• Integration into an enclosure is required for safety
• PWM-controlled power is fed to the motor ESC (See next page)
• Power supply must be compatible with the ESC
• Power supply provides voltage control
• ESC provides commutation
• Same power stage can be used with Welder Power Supply
• Input voltage to Power Stage can be 2-fold:
• 120AC rectified - for 24V DC motor
• 24VDC battery bank (from Day 4) - for welder power supply
• Power input is scalable to 6kW (~250A at 24V)
• Experimental power supply without proper heat sinking - just very small duty cycle for testing the power of power electronics

50A 1000V rectifier $2 ea

Power Supply Rectifier:

ESC Components

Motor ESC Integration

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Building the ESC: how it works - from AmazingDIYProjects

How it works on the high power side:

The high power side turns the batteries DC into AC in crude and simple mechanically-

electronic manner. Start out with a HexFet power transistor named: IRFP3703 (12-18V) or

IRFP3710/IR (up to 48V).

The IR-diodes sends out a light beam which can only reach the photodiodes when the ignition

hole on the rotor is in the right position. Once the IR-light reaches the photodiode the first half

of the high power circuit is activated. When the IR-light reaches the photodiode a small

current passes trough the photodiode, which triggers the transistor.

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As soon as the IR-light is turned off by the rotation motion of the rotor, the transistor is turned

off. The residual electricity in the Gate-connection is drained away trough the 1k Ohm resistor.

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The cycle repeats when the rotor hole lets the IR-light through to the next photo diode which

activates the other half of the high power circuit. The only difference is that the outgoing

cables from the power circuits are “swapped”; negative out circuit1 connects to positive out

circuit2 and positive out circuit 1 is connected to negative circuit2. .The result of the rotors

ignition hole passing the two photo diodes result in an alternating current, AC.

When the power is on, all the 20 electromagnets get activated and attracts/repels all 40

permanent rotor magnets at once. The next part of the cycle is started when the ignition hole

in the rotor lets the light beam from the second IR-diode pass trough to meet the second

photodiode. The whole cycle repeats with one important difference. The current runs the other

way trough the electromagnets causing them to repel the magnets that were attracted and vice

versa.

This is effective but has two major flaws:

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1. It does not self-start at times

2. You can not throttle the motor, there is only on and off. And this brutal way of starting the

motor often burns the power transistors at voltages over18 volts.

There is again an effective solution. By building a pulse width modulator, PWM, you can

easily adjust the power level. Notice that it is not the main power source we pulse directly.

Instead it is the IR-diodes that are pulsed! Since all the electronics of the high power side of

the motor is so fast, switching this setup works great without any lagging or other

complications up to at least 10kHz.

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Picture shows the components necessary to complete the electrical system of the motor.

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Universal Controller Light Dimmer + Welder Power Supply 1

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Topology sample (except work here should be on a 3D printed panel)

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Requirements

• Uses Universal Controller for the controller part
• Uses an external power stage
• Power stage contains a 120V full bridge rectifier + transistor to handle up to 2.4 kW of power
• Specify components such that 120V AC or 240V AC can be used as the input.
• First use case implemented is a 120V AC light dimmer for incandescent lights.
• Transistor uses a heat sink
• Power stage is on a 3D Printed board with all mounting holes 3D printed for convenience, and with 3D printed terminal blocks
• This includes input power + output power for a 100A welder
• Control board is 3D printed for hanging all components. Terminal blocks as integrated into the 3D printed board, so that part cound is minimized.
• Design of Circuit Board 3D print is in FreeCAD. See more here.
• Input to power stage is is a 120V power cord from the GFCI of the Universal Controller.
• 3D Printed Terminal Block design features 6 mm bolts with self-tapping hole through the plastic
• Used for power and signal wires
• Signal wires are the 22 Ga Cat 6 stranded
• Design is such that the single Universal Controller can run 2 or more power stages as above
• Either via the same pin
• Or by using multiple pins
• Scalability can be demonstrated up to any number of power stages, for example for a 400A welder power supply (10kW)
• Arduino Mega code is required as part of this project for the 120AC light dimmer and welder power supply
• Control is done via the knob of the LCD screen. LCD shows the duty cycle and voltage calculated from the duty cycle.
• Power circuit has no feedback at this point.
• The welder power supply is an AC-input, DC welder power supply controllable for 100A from each power stage, stackable to any amperage.
• Use a DIY welding electrode holder - and produce a replicable BOM for it.
• Both design and a tested system are required.

3D Printed terminal block with 6 mm self-tapping bolt

50A 1000V rectifier $2 ea

Universal Power Supply - Initial Design Requirement 1

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AC in

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DC in

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DC out

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Signal Input

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Transistors

Cordless Welder Power Board

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Requirements - Power Supply -

• Uses Universal Controller for the controller part
• Same hardware as AC welder power supply
• Power hardware circuit has terminals for connecting AC or DC power as the input
• DC is from battery pack (no rectifier needed)
• AC is from wall outlet (rectifier is needed)
• Stackability and power input flexibility are included
• Circuit design required in KiCad. Design includes the RAMPS board connection

Cooling Fans if required

Arduino