Telephone line over voltage protection: Here is my surge protector circuit design from 1995. It was available as a commercial product (with some small updates) for over 20 years. It did it’s job well, keeping the connected systems well protected. While modern communications have largely shifted to fiber optics and digital packets, legacy copper pairs →
FCCID.io is a free website for looking up records from the U.S. Federal Communications Commission (FCC) equipment authorization database. Most electronic devices that emit radio frequency energy, such as phones, routers, Bluetooth gadgets, remote controls and IoT modules, need FCC authorization before they can be sold in the United States. Each authorized device gets a →
So it’s this month that the NE555 really has its 55th birthday – but still going strong! Happy birthday 555! Look this video: Check also older 555 post https://www.epanorama.net/blog/2011/02/07/555-timer-design-contest/ →
The NE5532 is a classic, highly regarded dual low-noise operational amplifier designed specifically for high-performance audio applications. NE5532 is a dual monolithic, bipolar, internally compensated operational amplifier (op amp) for audio applications introduced by Signetics (now part of NXP Semiconductors) in 1979. The 5532 is fully bipolar, with the exception of a sole JFET within →
Anyone who regularly builds circuits or repairs devices wish they had a good LCR meter. With such an instrument, you can easily and accurately measure resistors, capacitors, and coils. The FNIRSI LC1020E is a handheld LCR meter designed for hobbyists and repair technicians who need more features than than a standard multimeter or basic LRC →
For a change it is nice to see circuit designs that would work posted to Facebook (most AI Slop circuits seen in Facebook do not work at all). Even those circuits would work, those circuits are potentially very dangerous circuit if not built exactly right. The biggest dangers are electrocution and fire. Start with circuit →
Have you ever experienced a malfunctioning device without the slightest idea as to what the issue might be? Typically, this issue is due to a blown fuse. This basic circuit published at https://www.facebook.com/share/p/1Gi4UZHpVh/ claims to be able to serve as an instantaneous way for you to detect whether it is in fact due to a →
I saw this viral circuit in Facebook https://www.facebook.com/share/p/1EEBkqkNr3/ It is a working concept but bad viral implementation: That 100 ohm resistor will heat up and consume the battery quite quickly. The 100 ohms resistor is so low value that it can potentially damage the transistor because maximum allowed transistor base current is exceeded when alarm →
I saw this circuit in facebook at https://www.facebook.com/share/p/1FF5z48oYV/. The screen capture is included here under fair use (commentary and critique). The good thing is that this is a simple circuit, but the disadvantage is that there is NO sound out with this design. – there is a battery drawn without clear indication of the operating →