HackerBoxes 0017: Power Maker

Introduction: HackerBoxes 0017: Power Maker

Power Maker: This month, HackerBox Hackers are exploring power electronics including various power supply converters. We are also modifying surplus power supplies into laboratory, bench supplies.

This Instructable contains information for working with HackerBoxes #0017. If you would like to receive a box like this right to your mailbox each month, now is the time to subscribe at HackerBoxes.com and join the revolution!

Topics and Learning Objectives for this HackerBox:

  • Define Power Electronics and describe its importance
  • Explain the difference between linear and switching mode power supplies
  • Identify boost, buck, and buck-boost type switching power converters
  • Power 5V USB devices using two AA cells into a boost converter
  • Assemble a DIY USB power pack based on Lithium batteries
  • Measure 5V USB power supplies under various resistive loads
  • Modify and Fabricate a Laboratory Bench Power Supply
  • Augment a fixed switching power supply with a variable output rail
  • Upgrade a Serial to USB bridge module with a linear regulator
  • Control Power Relays using Wi-Fi Internet-of-Things technology

HackerBoxes is the monthly subscription box service for DIY electronics and computer technology. We are hobbyists, makers, and experimenters. And we are the dreamers of dreams.

Step 1: HackerBoxes 0017: Box Contents

  • HackerBoxes #0017 Collectable Reference Card
  • Elite Maker Bench Supply Conversion Kit
  • 5V USB Boost Supply (0.9V input)
  • 5V Micro USB Lithium Battery Charger
  • CP2102 MicroUSB to TTL Interface Module
  • ESP-01 8266 Wi-Fi Module
  • Opto-Isolated Dual Relay Module
  • AMS11117 Linear Regulator
  • USB Power Tester
  • Power Resistors (10 ohm Loads)
  • Dual AA Battery Holder
  • USB Power Break kit with alligator clips
  • DuPont Female-Female jumper wires
  • Utili-Key 6-in-1 Key Ring Tool
  • Exclusive Power Maker Keychain/Pendant
  • Exclusive HackerBoxes Power Maker Decal

Some other things that will be helpful:

  • Soldering iron, solder, and basic soldering tools
  • 2 AA battery cells
  • Rechargeable Lithium battery
  • Tools and PC Power Supply for Lab Supply Conversion

Most importantly, you will need a sense of adventure, DIY spirit, and hacker curiosity. Hardcore hobbyist electronics aren't always easy, but when you persist and enjoy the adventure, a great deal of satisfaction may be derived from persevering and getting your projects working. Just take each step slowly, mind the details, and don't hesitate to ask for help.

Step 2: Introduction to Power Electronics

Power Electronics is the application of solid-state electronics to the control and conversion of electric power.
(Wikipedia Entry)

AC to DC Converters are also called rectifiers. The are the most typical Power Electronics circuits found in the power supplies of many consumer electronic devices, such as televisions, personal computers, battery chargers. You probably have numerous of these around your house in almost anything that plugs into wall power (which is AC).

DC to DC Converters are used to convert one DC voltage to another DC voltage. These are often found inside of electronic systems downstream from an initial AC to DC converter to create various other DC voltages. They are also often found inside of battery powered systems to convert the voltage supplied by the battery to the voltage(s) required by the system. Two common types of DC/DC converters used in hobby electronics are linear regulators and switched-mode power supplies.

DC to AC Converters should be noted for completeness. They are generally called inverters or power inverters. You may keep a power inverter in your car, boat, or RV to convert the 12V DC vehicle supply to 120V (or similar) AC "wall power" or "mains power" in order to supply electricity to small appliances, pumps, and so forth.

Additional Resources

Step 3: USB Power Breakout Leads

As hobbyist and commercial devices increasingly leverage USB-style power connectors to provide 5V, it is useful to have a set of USB power breakout leads for experiments.

Start with a Male to Female USB extension cable, and a pair of alligator clip jumpers (one black and one read). Cut all three in the middle as shown in figure A.

Next, identify the +5V and GND lines. These are usually red and black, respectively, but you can test them with a voltmeter. The other two lines (USB signal will be lower voltage).

Finally, solder the alligator leads to the USB lines and complete with shrink tubing as shown in figures B and C.

These breakouts can be used to clip 5V into a circuit (or onto a load) from any USB power source. They may also be used to clip onto a supply and then plug in a 5V USB load.

Step 4: USB Power Tester

A pass-through USB power tester can measure current and voltage of the power supplied by a UBS port. It can be used with a phone, mobile power pack, or any other load. The USB Power Breakout Leads from the previous step may also be used with a power dissipating resistor (or combination thereof) as a load.

Operating Parameters

  • Input Voltage: 3 - 7V
  • Input Current: 50mA - 3500mA
  • Capacity: 0 - 19999mAh
  • LCD can display voltage and current simultaneously
  • Data storing feature
  • High and low voltage alarms

The small button can be used to cycle test data.

Consider loading with various series and parallel combinations of the ten ohm power resistors. Do the various measured currents correspond to the calculated resistance loading 5V according to Ohm's Law?

Step 5: DC-to-DC Boost Converter Power Supply

A Boost Converter is a specific type of switched-mode power supply that can step up a lower voltage to a higher voltage.

This particular Boost Converter module can convert any DC voltage from 0.9V-5V to a nicely regulated 5.0VDC USB-style supply. The switched-mode used is Pulse-Frequency Modulation (PFM).

Powering with two AA cells can supply an output current of 500 ~ 600mA. A single AA cells can supply an output current about 200mA.


  • Input voltage: 0.9V - 5V DC
  • Output voltage: 5V DC
  • Up to 96% Efficiency
  • Dimensions: 34 (mm) x16.2 (mm)

This video details the operation of Boost Converter Circuits and even how we can make our own from scratch.

Step 6: Lithum Battery Charger Module With Battery Protection

The Battcher Charging module features the TP4056 (datasheet) Battery Management Chip and the DW01A Battery Protection Chip with 8205A Dual MOSFET


  • Input Voltage: 4.5~5.5V
  • Full charging voltage: 4.2V
  • Max output current: 1A
  • Indicator LED: (red = charging, green = charged)
  • Input: Micro USB Port
  • Dimensions: 25mm*19mm.
  • Use with 3.6V, 3.7V, 18650, polymer, and other lithium batteries
  • Use with single-cell lithium or lithium multi-section in parallel

Here is a video detailing operation of the battery charging module.

This module, the boost module from the previous step, and a Lithium cell can be combined to create a DIY USB Power Bank as shown in this Instructable.

Step 7: Bench Supply Conversion Kit - Introduction

This Elite Maker activity starts with scavenging an ATX-Style Power Supply from a scrap desktop computer. The parts in the Conversion Kit are used to transform the scavenged supply into a Laboratory-Style Bench Supply. A power supply from an old PC should be easy to locate under your desk, from the IT department, or a thrift store. If all else fails, you can purchase a new, but inexpensive, power supply such as this one.

Bench Supply Conversion Kit Contents:

  • Elite Maker Bench Supply Overlay Decal
  • Five Red Binding Posts with mounting hardware
  • Three Black Binding Posts with mounting hardware
  • Variable Buck-Boost Converter with 1.2V to 35V output
  • LED Panel-Mount Voltmeter
  • Power Switch with mounting hardware
  • Potentiometer 10K with mounting hardware
  • Aluminum Knob for potentiometer
  • Ten Ohm power resistors
  • Various Heat Shrink Tubing
  • Four Adhesive Rubber Feet

Other Items to Consider:

  • Soldering Tools
  • Hand Drill or Drill Press with standard bits
  • Nibbler Tool
  • Files (flat and round)
  • Deburring Tool
  • Hot Glue or Epoxy or Builder's Adhesive

It may be helpful to review this very detailed tutorial for a similar project.

This Instructable also covers a similar project.

Step 8: Bench Supply Conversion Kit - SAFETY FIRST


Power Supplies are dangerous and can hold charge long after they are unplugged. Before opening a supply, or even just working with the external output leads, unplug it from the wall and drain the output capacitors on EVERY power rail (each different voltage). Connect one side of a power resistor to Ground (any black wire) and then touch the other end of the power resistor for a few seconds each to 5V, 3.3V, 12V and so forth to drain each rail. Consult the color-code chart here as a checklist for the rails to drain. Do this every time you power the supply down and then need to work on it again.

If you do not feel comfortable working on your power supply, buddy-up with someone from a local Hacker Space, Maker Lab, or Ham Radio Club for assistance. Better safe than sorry!


Working with power tools, or even hand tools that are capable of cutting metal, is dangerous. Again, someone from a Hacker Space or Maker Lab would probably love to help you out before you cut a finger off or drill a hole in your spleen. Wear safety goggles. Seriously.


This conversion project is advanced and difficult. Slow down, take your time, read all instructions through first and proceed with great caution. Take plenty of time to plan your project (more on this later). If you decide not to break into your power supply, there is no shame in implementing an external option such as this one. You can put the binding posts into some perf board or plastic paneling and solder up the external leads from the power supply.

Step 9: Bench Supply Conversion Kit - Mechanical Modification

The follow steps can guide the process to mechanically modify the power supply housing:

  1. Unplug the power supply.
  2. Completely drain the capacitor charge on each and every rail.
  3. Cut all of the external connectors off leaving about three inches of wire to work with.
  4. Open the belly of the beast.
  5. Note how filthy it is and clean it.
  6. Examine the empty space inside the housing.
  7. Plan the location for the binding posts - use overlay decal as a guide.
  8. Plan the location for the power toggle switch.
  9. Is there room for the variable supply components inside?
  10. Completely Disassemble the Power Supply to just the housing.
  11. Cut the holes (see notes below).
  12. Apply a coat of spray-paint (optional).
  13. Apply the overlay decal.
  14. Mount the binding posts into the housing.
  15. Mount the variable supply components (optional).

Regarding the holes, cut-out sizes are:

  • Binding Posts - 7.4mm (5/16 inch)
  • LED Volmeter - 45 x 26mm
  • Potentiometer - 9.5mm (3/8 inch)
  • Toggle Switch - 6.4mm (5/16 inch)

Consult this handy chart when finding nearest drill bit sizes.

Variations: The Overlay Decal may be cut apart such that portions of it may be used in different areas of the supply enclosure as space permits. Furthermore, when the variable supply is not being incorporated, the rectangular LCD voltmeter outline may be removed. Also, the strip of title text along the top of the decal may be placed elsewhere as in the example shown.

Step 10: Bench Supply Conversion Kit - Electrical Assembly

Using shrink tubing as necessary, wire everything up.

  • Attach power rail wires to the binding posts (note color codes).
  • Attach the skinny green wire from the motherboard connector to the toggle switch.
  • Attach one of the ground wires (black) to the toggle switch.
  • You may need a load resistor on the 5V or 12V rail (to ground).
  • You can usually ignore the brown 3.3V sense wire.
  • Consult the next step if you are including the variable supply option.
  • Clip off any unnecessary wires.

Once everything is wired up, reassemble the power supply being very sure to securely reattach the chassis ground if you removed it early.

Attach adhesive rubber feet to the bottom of the supply housing to protect your bench/desk.


If your scavenged supply already has a power switch (usually at the AC input lines), It is fine to just use that as your power switch. You can leave out the toggle switch supplied in the kit and just short the skinny green wire from the motherboard plug to ground (a black wire). With that short in place, whenever AC power is switching on by the original switch, the switcher will turn on.

If you do use the toggle switch, it should be wired between the skinny green wire on the motherboard connector and ground. The little metal toggle switch should not be anywhere near the fat AC wires coming in from wall power even if one of them is also a "green wire".


Some PC switching power supplies will not turn on or stabilize without a load. Some do not need a load at all. If your supply needs a load (doesn't appear to work correctly without a load), you can use one or more of the ten ohm power resistors. The load should be placed on the rail with the highest current output rating. This is generally 12V, but sometimes might be 5V - check your supply specs. The best option is two resistors in serial (20 ohm) between the rail and GND. If that doesn't work, drop it to one resistor (10 ohm) to draw more current. Sometimes a load on both 12V and 5V might be necessary, but that is very rare. Keep in mind that If someone else did need loading resistors or not is a function of their power supply and will not necessary apply to the supply you are using. If you do end up needing load resistors, try to use the highest resistance that works to minimize the current draw. Remember that these resistors will always be drawing current (wasting heat) when the supply is on.

Step 11: Bench Supply Conversion Kit - Variable Output Option

Note that the variable output supply can be integrated into the bench supply (space permitting), or built up onto an external carrier, or omitted entirely.

The variable output is achieved using a buck-boost converter based on the XL60009 (datasheet). The buck-boost module can take any voltage from 5-32V as input, so either the 5V or 12V rail may be used.

The output voltage is continuously adjustable from 1.2V to 35V using a 10K potentiometer. The buck boost module is manufactured with a tiny 10K trimpot. The trimpot may be removed and replaced (as shown here) with the supplied panel-mountable, full-sized 10K potentiometer. An aluminum knob is included for the potentiometer.

The LCD panel-mountable voltmeter can display the present output voltage from the buck-boost converter, which is also wired up to the VAR(iable) binding-post. The Voltmeter has an integrated 0.56 inch LCD display and is capable of measuring 0-100 VDC.

The voltmeter has three wire leads (red, black, and white). The red wire is the operating supply for the meter and requires 3-30VDC, so it may be connected to the IN+ pad of the buck-boost supply (either 5VDC or 12VDC power rail). The black wire should be connected to the IN- pad of the buck-boost supply (GND). The white wire is the voltage to be measured and should be connected to the OUT+ pad of the buck boost supply which also connects to the VAR binding-post.

Here is an excellent video on the operation of buck-boost converters.

Step 12: Bench Supply Conversion Kit - Drive Bay Implementation

The binding posts can be also be mounted into a drive bay filler plate and spliced into the power supply leads. We wouldn't recommend doing this with a mission-critical PC, but if you already have a machine on your workbench for programming devices or running instrumentation, you can take advantage of its power supply as well.

Step 13: Modify the CP2102 Module to Directly Program an ESP8266

A common type of USB to TTL Serial Board uses the CP2102 chip (datasheet). The CP2102 has an on-board 3.3V regulator, but it does not supply enough current to power an ESP8266. However, there is plenty of current on the 5V rail since it connects directly to the USB 5V supply. Using an AMS1117-3.3 (datasheet) regular to convert some of the 5V current to 3.3V solves the problem quite easily and provides a great soldering exercise. The AMS1117 is a Linear Regulator variety of DC to DC power converter.

This Instructable shows this modification in detail.

Step 14: IoT (Wi-Fi) Power Controller

The ESP8266 module can be used to control a relay module over over Wi-Fi. Using the modified CP2102 from the previous step, the entire project may be powered from a micro USB port.

This tutorial, and many others, explain programming the microcontroller core of the ESP8266 via the Arduino IDE.

Several other Instructables, such as this one, demonstrate similar projects. Note that the one in the link is not powered over the USB module.


Switching mains power using power relays is dangerous. Such activities should be undertaken with great care, using properly grounded enclosures, and according to your local laws and regulations. If you do not feel comfortable working on power switching, we urge you to only work with switching low voltage signals. As suggested earlier, you can also buddy-up with someone from a local Hacker Space, Maker Lab, or Ham Radio Club for assistance. Better safe than sorry!

Step 15: Utili-Key 6-in-1 Key Ring Tool

The Utili-Key from Swiss+Tech is a 6-in-1 Key Ring Tool. It is a super-handy, ultra-lightweight multi-tool and the perfect functional accessory for the HackerBoxes exclusive PowerMaker Keychain.

The Utili-Key 6-in-1 Multi-Tool includes:

  • Flat Screwdriver
  • Phillips Screwdriver
  • Precision Screwdriver
  • Straight Blade Knife
  • Serrated Blade Knife
  • Bottle Opener

Step 16: Hack the Planet

Thank you for joining our adventures into power electronics. If you have enjoyed this Instrucable and would like to have a box of electronics projects like this delivered right to your mailbox each month, please join us by SUBSCRIBING HERE.

Reach out and share your success in the comments below and/or on the HackerBoxes Facebook page. Certainly let us know if you have any questions or need some help with anything. Thank you for being part of HackerBoxes. Please keep your suggestions and feedback coming. HackerBoxes are YOUR boxes. Let's make something great!

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4 years ago

My buck boost converter currently only outputs 54 volts. Even with changes in the variable resistor, there is no change. Checked to see if the resistor still works, which it does, and rest of power supply is working fine. Any solutions? It was working fine then I had to re solder the OUT- wire and it hasn't worked since then.


5 years ago

Anybody have success with the bench supply? I believe my load resistor setup isn't quite right. When the PSU is switched on, and i toggle the switch with the green cable going to ground I can see the fan stutter. I have tried the resistors one by one in series and in parallel. This is off the 5V rail, when a load is connected to the 12V rail the fan doesn't move at all. Any ideas?


Reply 5 years ago

Dan, you could try one 10ohm power resistor from 5V ground and a second one from 12V to ground. That is a lot of current to draw all the time, but it is worth a test to see if it can kickstart the switcher. If that doesn't work, I would check to make sure there aren't any shorts or other problems. If that does work, you can try reducing the current draw on 12V by using two resistors in series and see if that still works. If your supply has a main cut-off switch, turn it off (or just unplug it) when not in use, otherwise those resistors will always be on (wasting heat).


Reply 5 years ago

I actually ran into the same issue with this power supply https://www.amazon.com/gp/product/B01GUENTKC/ref=o...

Ran two 10ohm resistors in serial on the 12v, also ran 1 on the 12 and 1 on the 5, and 2 on the 12 and 1 on the five. The display would flicker 0.0 for a moment, same with the fan jerk, but then would turn off. Could get it to repeat this any time I connected the green wire to a ground. Not really sure what else I can do to try and kickstart it. I did only run 1 wire per post, but saw other videos where people ran every wire of a certain color to the voltage posts. Not sure if that makes a difference or not, however (I wouldn't expect it to).


Reply 5 years ago

I tried this but no luck. I am using the Logisys Power Supply that you linked in this post. My purple wire does present the 5V.


Reply 5 years ago

Ok, first at all, don't try this reply before get some confirmation from another experimented user, because I'm newbie on this.

bought the logisys psu too, and when I check it I noticed there are a
set of cables not listed in the color char, if you look close on those,
there are a pink set of cables, looks like orange but they are pink.

research, I found some PSU that has this pink cables for +5V sense, and
says it need connected with the +5V (red) cables in some cases to make
the PSU works.

Can't find like an official data sheet but I find the attached image, so my guess, that's why is not working.

some one can confirm this or give us some orientation. I didn't start
mine yet, because I want to have all, and want to use another case.

Another thing, in the chart says somenthing about the grey cable, is like an auto test.



Reply 5 years ago

This is interesting.

In my case, I used the cables from the drive's connectors, I get 3.3, 5 and 12 v (I use the brown cable to the 3.3).

So most of the cables on the motherboard connector are still there.

The fan spins and I have no resistor shorting 5v. The ground and the power switch (green to black) is working.

I have not tested with load though just volt meter.

However, when trying to install the buck converter the potentiometer is bad, on the left pin I have no current at all and on the right pin the resistance fluctuates a lot and the potentiometer works randomly, (I get 53v max).

In the meantime, I think I fried it, I accidentally reverse the polarity using a 3.7 v battery. Does anyone know if this buck converter has any protection?


Reply 5 years ago

Here are some pics to illustrate what I mean


Reply 5 years ago

Nice case 3D printed?


Reply 5 years ago

Ok, thanks for share this, so I have to check first all the voltages in the PSU before start cutting cables and test the components. I hope all mines are ok, specially the PSU.


Reply 5 years ago

I wanted this to be true, but I don't think it is. The pinkish cables you are talking about lead straight back into the 3.3V block.

Ok, so I have been looking at this, thought I saw something with the 12V rail, but it got me testing. It turns out that both my 5V and 3.3V are short to ground. I'm pretty sure that can't be right. I have disconnected and verified that nothing was touching each other. These are definitely short to ground and therefore to each other.


Reply 5 years ago

Did you tried keep apart the orange cables and the pink cables and see what happens? Let me know if you fix it, I have the same PSU.


Reply 5 years ago

Yes I tried that,but if you test the resistance you will find that the orange and pinkish cables are short to each other. The bigger problem with mine is that the red (5V) and orange (3.3V) are short to ground. You can test this before you ruin the power supply and hopefully have better luck than me.


Reply 5 years ago

Are you getting a new PSU?


Reply 5 years ago

Ah ok. I didn't connect it yet because I don't want to charge the capacitors, but I guess I'm going to test it w/ multimeter before do anything.


5 years ago

I finally got a new switch in to replace the one I melted from the original power supply. Got that soldered in and the whole thing worked like a charm.

Check out the video in my YouTube channel: https://youtu.be/hHqJRv_VO4M I'm just uploading the part 2.


5 years ago

Ok, I'd figure it out why mine doesnt works. The pontetiometer that came in my box is bad. Should check this before. I have to buy a new one.


Reply 5 years ago

My buck boost module keeps blowing my pots. It works the first time I turn it on but the second time the pot is already burnt out and the converter is outputting 54 volts. I went through three before I figured it out. I'll post again if I find a solution.


5 years ago

Anyone can recommend me a site where I can send a design for an acrilyc sheet and they can cut it and make the holes and labels for my power supply? I want to do it with all cables outside between the acrilyc and the original case, with some spacers.


Reply 5 years ago

ponoko does laser cutting I think