Heated Clothing Controller and Power Options Version 2

The final hurdle to finishing DIY heated clothing projects is often obtaining a power source and method to control the heat output. Heated clothing projects benefit from voltages higher than those of standard 5V USB which allows them to operate at a lower current. Fortunately USB Type C power banks with the Power Delivery feature can output 9V, 12V and 15V which allow for projects with higher wattage without exceeding the current limit of the power bank.

This project shows how to use a PWM motor controller / LED dimmer, and USB-C PD module to create a compact temperature controller that varies output between 0 and 100%. Another type of battery could be used instead by wiring an input connector instead of using a USB module.

The wide range of adjustability makes this controller helpful if your heated project ended up being hotter than anticipated.

A benefit of using USB-C modules is a consistent temperature for your projects. Regular batteries start at a higher voltage then drops as the battery drains reducing the heat output. The regulated output from a power bank keeps a level voltage the entire time.

By having the USB-C module connected to a DC connector, you can easily change project voltages by creating a new power wire with a different USB-C module, provided the motor controller supports that voltage.

This is a refinement of my previous controller project. By switching from a female to male USB-C board I was able to eliminate the need for a USB cable, and make it easier to change input voltages.

• Mini PWM Motor Controller
• Type-C PD Decoy Module of Desired Voltage With Male Connector

(the same listings generally have options for different voltages)

• USB-C Power Bank with PD Support for Desired Voltage
• LED for power indicator with suitable resistor (https://ledcalculator.net)

I'm using a high-intensity green LED, a red one I used before was very difficult to see in daylight.

• 22 AWG Silicone Parallel Conductor Wire

(link is for example, should be able to find shorter lengths instead of a full spool)

• 22 AWG Highly Flexible Silicone Covered Hookup Wire (optional, less bulky useful for wiring LED)
• 3.5 x 1.35 mm Female DC Barrel Connectors (3 if building 1 controller with 2 outputs)
• 3.5 x 1.35 mm Male DC Barrel Connector

(or whichever connector your heat project requires)

• Polyimide (Kapton) tape
• Electrical Tape
• Flexible Silicone adhesive such as E6000
• Assortment of heat shrink tubing

Tools:

• Soldering Iron and solder
• Soldering Flux
• Wire Snips

Before getting started it is worth thinking about where you plan to use the controller.

At first I had the input and output connections at the back. However I mount the controller in my jack with the dial pointed towards the zipper so I needed disassemble it and move the power input to the side pointing down towards the battery pocket.

I use this controller connected to extension cables run through the sleeves of a jacket to power a pair of heated gloves using one battery. So I added 2 output wires with one longer to reach across in front of me to the extension cable for the far sleeve.

Power Bank Selection

One important thing to note about power banks is that nearly all of them have an auto sleep feature. The heat controller by itself doesn't draw enough power to keep the power bank awake. So if the controller isn't on AND connected to a heating loop the power bank will go to sleep after a few seconds. You will need to press the wake up button on the power bank. For that reason I strongly suggest including a power LED on the controller to eliminate having to guess whether it is on or not.

For using my heated gloves I've been leaving the controller dial turned on all the time and use the power bank button to turn them on and off (my power bank turns off with a double tap). My power bank has a tiny flush mount button, so I super glued a little nub onto it to make it easier to press while it is inside my jacket and I'm wearing gloves.

In order to use a USB-C PD module you will require a USB Type C power bank that supports Power Delivery at the voltage you intend to use. You should also check the amperage output for the various voltages. I've seen some power banks that only output 1.5A at 9V while others will output 2A+.

These power banks are best charged using a USB wall charger due to their high capacity. Some of the power banks can only be charged through a USB C port, so you may also need a USB A to C adapter in order charge it.

Note

The PWM controller I use has a screw terminal block on the board. I removed the screw block and soldered directly to the board. Removing the terminal block proved very difficult. I needed to cut the plastic away and remove the pins one at a time. Even with a desoldering pump it was not easy to do. It is probably best to just use the screw terminals. The pictures show a mix of methods.

The parallel conductor silicone wire is a bit bulky. For the LED and power input jack you may want to use other silicone hookup wire if you have it to make wiring routing easier and the terminal connections less crowded.

Soldering Tip: Apply flux to connections before soldering. It make the soldering easier and result in smooth connections.

DC Power Input Jack

• DC barrel jacks are typically wired with the center pin as positive. You can use a multimeter to confirm which tab connects to the center pin (usually the shorter one).
• Solder wires to the tabs of a female DC barrel connector.
• Test fit the connector in its desired location and trim wire to necessary length. For the dimmer board I used, the power inputs are the outer terminals.
• Tin ends of wire with solder if using the terminal block.
• Wrap Kapton tape around the tabs to avoid shorting.

LED

• If adding an LED trim one leg and solder resistor onto that leg.
• If necessary add wires to facilitate LED placement and add Kapton tape around each leg to prevent shorting.
• Polarity is important for LEDs. The positive leg is longer. Looking at the top of the LED the positive leg leads to the smaller side of the junction inside the plastic.

Output Wires

• Add Female DC barrel jack(s) to wire of desired length for use as an output.
• Slide connector shrouds over the wire and screw onto the connector. I've found the strain relief tail on these shrouds to not be effective, so I snip them off and add a blob of adhesive later on.
• Tin other side of wire with solder if using the screw terminal block.

USB-C PD Decoy Module

• Solder wires to the outputs on the USB-C PD Decoy board (for the board I used positive is labeled V and negative G).
• Trim wires to desired length to reach from the battery to the controller (if unsure you can return to this step later).
• Wrap the board with Kapton tape.

Several times I've encountered problems with the male DC connectors I've ordered where they intermittently stops working. Most sellers have what looks to be the exact same model. The problem appears to be due to the center positive tab not being solidly connected to the pin, so I've been doing a small modification before I use them.

• Add flux to the ring shaped base of the positive terminal. Add solder to bond the ring to the pin.
• Slide of DC barrel connector shroud over the wire (this step is easy to forget).
• Solder male DC connector to the wire ensuring the center pin is positive.

Dimmer Board Cleanup

Using snips I did some additional trimming of the through hole pins on the back of controller board.

Attach the input jack wires to the corresponding inputs on the motor controller. For the board I used the inputs are the outer terminals.

Connect output wire(s) and LED to motor controller output (polarity is important for the LED).

Wrap the motor controller with Kapton tape. This will prevent shorting and will make it easier to remove electrical tape if there is a problem later.

Connect power cable and test before sealing the controller.

Controller Board

If using multiple output wires tape them together close to the board.

Use electrical tape to secure the power input jack. Add a piece of folded electrical tape between the two boards if necessary to support the PD board.

Wrap the board with electrical tape.

Add additional pieces to seal the ends and around the LED. It helps to cut a slit where the tape needs to go over the dial shaft and LED.

You may want to add Velcro to the bottom for attaching controller. I find the adhesive on peel & stick Velcro isn't strong enough so I use a silicone adhesive such as E6000 for a permanent bond.

USB-C Module

Either wrap the board with electrical tape, or several layers of heat shrink tubing. This will give you something to grab to pull the connector out of the battery.

Add silicon adhesive where the wire meets the module wrapping. In my case I also smeared a layer of adhesive over the heat shrink tubing. It dried clear and has a rubbery finish to improve grip.

DC Connectors

Add a blob of silicone adhesive where wire enters the connector shroud. This will help prevent strain on the solder joints.

I also glued a piece of plastic to the wake button on my power bank. The button is tiny and flush mounted which made it very difficult to press while wearing gloves and it was inside my jacket.