(1) Noise Filter 40 AMPS 12V HUM Filter Noise Engine Suppressor Wire IBNF40

Items work amazing stop all noise coming through my alternator would by again

Works as it should

Filter does not work at all. Never buy again.

The first thing I noticed was the insulation on the wires. It is not typical automotive grade insulation, very thin and I have no idea about the temperature rating - but obviously done for the "Glitz" effect. Terminal are cheap and the insulation comes off easily. Not good shrink tubing. BUT, this is minor - IT GETS WORSE !I was suspicious of the leads since they seemed to be twisting in the grommets like they were not stress relieved on the inside. So, I opened the bottom. I had also notice that the bottom and mounting case flanges were not flat - leaving the case rocking on the mounting screws.What was found inside was absolutely dangerous.Summary of Problems:* Torroid Winding Wire rubbing case - DC Short Potential* Capacitor ratings underrated - Voltage and Temperature (If using in Engine Compartment - Serious Issue)Automotive Temp Range: −40 °C to + 125 °C. (Engine Compartment - Minimum) Caps rated at 105 deg C* Both capacitors have working voltage problems.* Missing two of the three mechanical (Zip Tie) stress relief ties - See photoThe torroidal inductor was mounted off to the side on the PC board (absolutely unnecessary) and the wires were rubbing on the side of the grounded can - A big short waiting to happen. See summary of measured dimensions in pics. They had made a lame attempt to insulate the interference fit and rubbing by putting double sided padded tape on the inside of the can on the side, but in my case, it was not stuck to the side, but loose in the bottom of the can and just fell out when I opened the can bottom and pulled the board out carefully. This circuit is a simple Pi filter. The input cap on the battery side is 1 ufd @ 50V. The output cap is 3300 ufd @ 16 volts. Both of these voltage rating values are very marginal. Current automotive designs can easily run the alternator battery buss up to almost 15 Volts. The current specification for Auto Buss Voltage is between 9V and 16V but, on the input side, transients can go as high as over 200V (See picture enclosed). In addition, on the output side, the 16V rating is lacking. It is not a good practice to run a cap right at rating. From Tyco Electronics Automotive Application Note, I include Figure 1(pictured) which summarizes typical transients that this unit will see on the input. Notice that transients of over 200 Volts are not uncommon. I am adding Vishey Tranzorb 50 Volt clamps on the output side and will increase the output capacitor to 3300 ufd @ 25Vdc WV (Working Voltage). This cap is a little under an inch high and about a half inch in diameter. It will fit nicely turned to the side which is how the PCB should have been laid out in the first place. The temp range will be increased to -40 to +125 deg C.The input cap can be improved to 10 ufd 200 Vdc and -40 to +125 deg C. This cap can be bought from Mouser and is only 3mm in Dia and 7/16th tall (Good fit) with an available part that costs $0.79 in small quantities. I would not attempt this rebuild if you do not have the experience.I am also changing out those glitzy terminals and covering the wire with automotive temp range capable shrink tubing and reinforcing the new terminal with high quality shrink tubing that will actually stay in place. As a summary.If you are going to be using this in the engine compartment, you need to seriously rebuild it as per above. If you are using it in an audio application in the passenger or rear compartments, you need to open it and check for/solve the mechanical reliability problems. Then hope that the engine compartment transients that are over 16 volts don’t make it back through the harness without some smoothing effect.This is a very poor quality control item obviously and it could be seriously dangerous if the internal components contact the case. and . . .It should also be noted that all of the large leads are attached to the PCB just with solder. Any good design engineer knows that solder is not a structural material and that you always should make a mechanical thru hole or crimped connection before soldering. If the strain relief zip ties are missing, then lead fatigue will be an issue. Put these in place for sure. Good Luck.

You can probably find something better. Sketchy design.