Use of Power Modules in IoT Hardware

If you are in the business of designing IoT devices and you are on the next stage of your design phase, the power supply. I mean what is a great design, without the right power supply correct? Let us explore some of the options:

External Power Chargers

The first and obvious option would be to power your device using the good old external power warts. Whether you have a USB input and have your consumer purchase an external power wart to plug into an outlet and into your device. Such devices are great for devices that would sit on a desk, or can go a distance away from the outlet. Also, keep in mind that these external USB power warts can exert external noises and have undesirable effects on your application.

USB Wall Charger - 5V, 1A (Black)
Source: Sparkfun

Batteries

The next logical option, especially for IoT is the use of batteries as well. This is a great option if your application demands that the device must be so mobile that it must be powered using batteries. With today’s chips and design techniques we can achieve long lasting devices with just one AAA battery. It is a great option with sometimes minimal external parts, more than likely you would need a battery controller if you are charging the battery otherwise you would also need a boost converter to enhance and regulate the voltage. You also need a monitoring technique to ensure that batteries power as it is reaching its end life that the user is notified and an action is taken to relieve the device. Your main concern here would be to ensure that every design decision you make is to ensure that all components are low power consuming.

Covered Battery Holder for 2 AAA Batteries with On/Off Switch
Source: Battery Mart

Direct Outlet Connection – Custom Design

One of the best options that you could have when designing an IoT device is to have to design the board to plug into an outlet. Then you would have no problem with power usage, as we know most IoT components are minimal on the power consumption anyway. The first idea that comes to mind is, why not completely designing a custom on board AC/DC conversion and regulating to the desired voltage. In which in most of the IoT systems is 3.3V, that is a very low voltage from the mains usual voltages. The issue here is that at first it might seem like the best option to save on cost, while that might be true on the components side but what you also need to consider is many of the side items and regulations that we fail to accommodate. Such as UL certifications for household safety, EMC for either Class A or Class B (class A is mainly for industrial applications and class B is for households applications). Now, you have to learn many of those regulations on your own, but it can lead to troubles if you are trying to hit a deadline or get your product out as fast as possible. There is also the costs of EMC regulations testing costs and retesting because in more complex systems it is more than likely that you might have missed something. These designs can also be very ugly, remember this is just for the power supply? Take a look at this example:

Source: Arrow

Power Modules On-Board

Onto my favorite part, Modules. When appropriate (and only when appropriate as sometimes there are designs or requirements that would require the use of more complex power supplies) the use of power modules can be such a great relief and is like taking the express lane in rush hour straight to production lines.

With the use of Power Modules that are UL certified, CE, FCCm EAC with more safety certifications would make them an easy integration in your design. Every component is engineered in a way to fit into a small enclosure that would only expose through-hole rods that sit right onto any PCB, and all you would need to supply is the AC lines and you are good to go with DC on your board. This is one of the designs that I am working on recently that shows the difference of components versus the custom made power supply.

All of the filtering and safety components are in the enclosed enclosure. My top choice when it comes to power modules would have to go to Recom. This is a manufacturer you can trust with all your power supply needs, they are advanced and running at the speed of our technology needs. They also provide many benefits for their customers such as design review, product selection support and EMC testing facility to conduct free testing for their customers. The tests conducted at Recom are pre-testing meaning they cannot certify for you but they can give you a pretty good idea if you are going to pass or fail, and you can fix the problem!

AC/DC, 1.0 W, Single Output, THT RAC01-C Series
Source: Recom

Please make sure you are using caution when designing or tampering with mains as it is live voltage that can terribly harm or worst kill you. In no way do we at all recommend that anyone without the proper certification and experience to tamper with outlet mains live voltage. Please be to consult someone with more experience if you are going to conduct your own experiments.

We are not affiliated or paid by any of the mentioned third-party companies to write this article. We are simply a fan of their products and want to learn more about the future of such products. Nothing on here that we recommend that we would not use ourselves. Please feel free to leave your feedback!

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