Review on RioRand 5 Pack Boost Converter Module: XL6009 DC 3.0-30 V to DC 5-35 V, Adjustable Output Voltage, Step up Circuit Board - 4A by Jack Collins

I rarely give a product 5 stars but this product is an exception. What struck me from the start was the professional packaging of each board. They were individually sealed in an anti-static bag. I received the electronics (LASER, 365nm UV LEDs, etc.) in either a regular plastic bag or just a mailing envelope. Then there's the price. Less than $2 each! I originally intended to build an adjustable regulator based on the LM2576-adj; However, this board is exactly what I need for the lab power supply I'm building and it also plugs into a solar charger. In terms of device performance under load, I modified one block by replacing the output cap with Arctic Alumina thermally conductive epoxy to bond a Cosmos RAM copper heatsink to both, available through Revain. (See attached image) A word of caution - Arctic Alumina Gel at 3 minutes and hard as a rock at 5 so work fast and remember that once the epoxy has cured the heatsink won't come loose without cracking . I connected an unmodified device to my oscilloscope and connected a homemade dynamic load to the output terminals. The open circuit voltage was set at 12.6V. With a load of 1 mA, 3 µs pulses were present at the 56 kHz DC output. The pk-pk amplitude was 64 mV. With a current of 1.5 A peak-to-peak, the amplitude increased to 134 mV with a pulse width of 6.4 µs. One with a 1000 µF cap at 1 mA had a pulse width of 2.8 µs and a peak-to-peak amplitude of 16 mV. At a current of 1.5 amperes, the pulse width increased to 7.8 µs with a peak amplitude of 33 mV. A significant improvement over the unmodified version. Both versions lost their stabilization at about 1.75 amps, which I attribute to the time constant of the DC source I was using. (18Vp-p full wave rectification converted to 4700uF capacitor). I did notice that even though my load got significantly warmer, the regulator was only a few degrees above ambient, so adding a heatsink might have been overkill. Since I am building a lab power supply and want the output to be as clean as possible, I modify another board and use a low pass filter on the output of each board. Warning: The NatSemi datasheet recommends not to exceed 820uF for the output capacitor. I believe this is because too large a capacitor can prevent starting as it looks like a very low impedance at power up. I haven't noticed any problems. I'm very happy with the performance of the board and would recommend it to anyone looking for a cheap, reliable controller board. However, depending on the application, board modification may not be necessary. Note that the negative terminal of the output cap is soldered to the ground plane and is difficult to remove. I have many years of experience soldering both thru and surface mount devices and it took a bit of effort to clean the ground hole. I would also recommend if you choose Arctic Alumina thermal epoxy resin that you download the safety data sheet and instructions for use from their website. So I could use a board mounted potentiometer to control the output. Since the potentiometer was about 4 inches from the board, I used a RG218 mini shielded coax cable to connect the board to the potentiometer to minimize stray fields affecting device stability. I wanted the power switch to be on the front but I was concerned about getting the hot side of the wire past the controls. This problem was avoided by twisting the wires and tying them close to the case, then covering them with conductive copper tape for additional wire shielding. Below are two types of finished power supplies. The front panel turned out to be very good, and the internal layout is neat. Most details are available from Revane. The panel meters are Hopesun's 15 volt analog D'Arsonval motion meters. I used them because they don't require power and if I need accuracy I can use my DVM. The device cost me about $60 to build, compared to over $200 for a decent lab source with similar performance. All parts are new. I originally wanted a multi-turn potentiometer to control the voltage, but a 10-turn potentiometer would cost me $10; The 1 draw pot cost me just over $1.00 and was just enough for my needs. For really accurate voltages, I have a device I designed that uses 10-turn potentiometers and a precision op-amp circuit that is stable to 0.1mV, making it great for open-loop op-amp gain testing. Anyway, I'm very happy with the delivery. It supplies 1500 mA at 12 volts. At around 15 volts the current drops to around 750mA since the transformers I use only give a filtered output at 21 volts. The current consumption begins to exceed the time constant of the filter at a voltage of 15 volts. never mind However, I probably should have used larger transformers, but that would have added weight and messed up the layout. The goal of this project was to build a double isolated power supply that emulates a differential power supply without breaking the budget as most projects I work on use +/- power. I'd be more than happy to provide specs, schematics, and construction notes if anyone is interested.