Power Supply Filtering Board Power Supply Filter EMI High Frequency Two-Stage Power Low-Pass Filter Board for Power Supply 6A 25A Optional(25A)

I've provided solar power for the last few summer field days. We had already noticed the 120v inverter was generating unacceptably high interference on our radios, but this last event we also realized the solar controller was generating interference, and that one wasn't really optional so we needed to find a way to filter our power This sort of interference is going to come from any switching power supply, inverter, power converter, or even other accessories generating "noise" (EMI) on the same power line.I've been assembling a variety of of different filters to test (as well as purchasing a few fully-assembled units) to see what works the best. Unfortunately, EMI can come in many forms, and one filter can't protect you from everything, so it's good to have options so you can go with what works for your specific EMI problem. In my tests however, this specific filter worked extremely well for any interference coming over the power wires. This was a 12 volt DC power, but this filter works equally well for 110VAC also. (the capacitors are rated 310 and 400 volts, so 220 should be fine also, but don't try 440, and it won't work with 3-phase)I tested several filters, including a professional CUI, using a large battery as the power source, with a 120VAC true sine wave inverter powering a 750w ceramic heater as a source of EMI. As soon as the inverter was turned on, the radio receiver (IC-7300) powered from the same battery immediately showed significant interference on 40m/80m, with regularly spaced S-5 spikes on the waterfall. These spikes went well over S-9 when the heater was turned on, loading down the inverter and amplifying the interference it was producing. For those not familiar with radio, this level of interference made it almost impossible to hear what was being received.This filter and the CUI both were able to remove the unloaded noise, but when the load was turned on, S-5 spikes appeared through the CUI. This filter however, was able to completely remove the loaded spikes from the waterfall, leaving a totally-acceptable faintly-audible sound at the exact points of interference. I attribute this extremely effective performance on this filter being a two-stage common-mode filter. The CUI I was comparing it with used a single stage common-mode, followed by a high-side differential mode. (just a choke in series) The CUI did better when I placed a second one in series with it, but THIS filter can clean up even strong interference in one shot.Just to clarify for the seller, the picture in the listing includes a shot of the 25 amp filter, with the 15 amp filter below it. You only get the one you order. They should update the listing so that the image changes to just one board or the other when the buyer selects which board they want.Also, you don't really need a manual, since it's a "plug it in and it works" sort of thing. Grounding is optional but is likely to help if the interference is much higher frequency or RF noise ON the frequency you are trying to receive. (I suspect most people considering this filter are dealing purely with power line EMI and so connecting the ground won't help them much if at all) The ground connection is in the middle on both sides, and the outer two contacts are for your Live/Neutral or +/- power connections. Live/Neutral or +/- can go to either connection, the circuit is symmetrical and not polarized. Either end of the board works equally well as input or output.Though if you're not able to figure this out on your own, you probably shouldn't be ordering this product for 120VAC filtering, as I question you can safely handle or install it. This isn't a consumer-packaged part you can just leave plugged in laying in the living room with the kids. It's a component, with exposed live contacts, and requires competent installation to be used safely. If you're planning to use this for 110vac or higher, don't try it if you don't feel comfortable replacing an AC outlet. If you're going to use it for 12VDC like me though, its quite a bit safer, though when dealing with any sort of power you can still start a fire if you misuse it.I've purchased a total of four of the 25 amp boards. All were identical, with clean assembly, good solder joints, and quality components. The boards were shipped in adequate bubble wrap via UPS. I couldn't ask for better. I'm recommending this board to all my friends that are having problems with EMI on their radios in their home or in their car.

Addressable LED light controllers/strips can be very sensitive to noise from the most 24V DC power supplies. This filter nailed it when the the usual DC filter couldn’t. Go figure. It’s not polarity sensitive so just figure same side goes through. Additional filtering is possible by running house ground up the middle but I didn’t need it. Clean zero flicking or anomalies in the light output. I would have given it five stars but I tested it on another AC household device and it got hot with a 10 amp load so 25 amps is highly overrated so be CAREFUL and test it for your load and heat accordingly.

This makes this purchase too highly priced. There are lower prices for the same 1 unit at other suppliers.

Had a Bluetti "Go-box" (aka. solar generator) that was putting fairly good 12VDC Power but it wasn't clean enough for my needs. I run some HAM Radios and noticed some RF noise when I use the Go-Box. This filter cleaned up that noise. I recommend that if you require clean DC Power from your "Go-Box" or any solar generator, use this filter. Connect your dirty DC Power to the side that says "LINE". You'll need to connect your positive (red) lead to the "L" screw (Note: Ignore the numbers and look at the PC board for the letters), then connect your negative (black) lead to the "N" screw. The OUTPUT will be on the "LOAD" side of this filter on the Left and Right screw terminals.. Also, I oddly got a tiny improvement in the filtering by attaching a short wire to the middle "GND" screw on the board. the wire doesn't go anywhere, it just a short run of wire. This, of course, is totally optional. the board works fine without it. To finish up, I got a 2" wide heatshrink tube and placed a section over the entire filter after I had it wired up. Then hit it with a heat gun. Gives a nice amount of protection to the filter.Good Luck ;)TO THE PEOPLE THAT THOUGHT THERE IS TWO UNITS IN THE PACKAGE: You're incorrect! That's just a photo of the 6AMP unit next to the 25AMP unit.

My DIY subwoofer amplifier is noise-free so I guess this filter is doing it's job. Probably overkill for a project like this using a switching power supply, but I wanted to make sure the amp wouldn't pick up any AC noise and also make sure the power supply didn't backfeed any ripple. The screw terminals are easy to use with spades or even bare wire if you're the adventurous type. Standard standoff holes made installing in the case a breeze. This board has AC in and out with a common ground. You can use it without the ground, but you'll lose out in one of the shunting varistors. Not a big deal. Board seems to work great without the ground.

I had high hopes that this would get rid of the 15Khz noise that my Inverter Generates on most Bands but it did nothing! I highly suggest you run your radio from a UPS or Car battery first and see if the noise is really coming in through the AC line. I suspect that the noise is actually generated by the MPPT's on the Inverters and is picked up by the Antenna. If I turn my beam away from where my Inverter is located the Noise drops off significantly.I am giving it four stars because it probably is a good LP filter but it is not the solution for my problem.

There is only (1) of these in the shipment, not (2) as shown in all of the pictures.

I have a solar panel monitoring station sharing the same outlet as my CNC machine. When the CNC machine was on my monitor could not talk to the panel inverters due to all the noise on the line. I used the 25A filter between my CNC power strip and the outlet and now I have no noise issues. Please be aware this unit is exposed, so you must use an enclosure to avoid having a potential shock hazard.

Advertisement say 2 units but shipped only one

If you think your going to get 2 units think again you get 1. If you check in the details it does list 1 item and the the product does work.

Unfortunately, the coils are wound in such a way, that they only choke common-mode, high-frequency currents. They will not impede any differential-mode currents. Yet, the manufacturer cannot have intended for it to be that way, because the capacitors are arranged, to shunt out and neutralize differential-mode voltage-swings.