This is a telephone line over voltage protector. This is basen on a design I did originally around 1995. Has been available for almost 30 years. That white thing is a deal gas discharge tube over-voltage protector that dissipates most of the over-voltage surge. It is followed with two other layers of protection (VDR and →
There are two main types of transistor: bipolar junction transistors (BJTs) and field effect transistors (FETs). The invention of the transistor in the 1940s was a major turning point in the history of electronics. The bipolar transistor was the first transistor to be invented, when one simply says “transistors,” it sometimes means bipolar transistors. BJTs →
VituixCAD is loudspeaker simulation software. Design philosophy is to simulate loudspeaker behavior in full space or half space. Even though emphasis is on power response, polar responses and directivity index, it is possible to design a loudspeaker without comprehensive angled measurements. This is not encouraged though. Software package includes everything one needs for simulating and →
A battery can be regarded as an ideal voltage source in series with an impedance, which is called internal resistance. When the battery works, the voltage output is lower than the open-circuit voltage (abbreviated as OCV). The difference is the voltage drop caused by the internal resistance. Internal resistance represents the battery’s limiting factor to →
There are applications where measurement of low resistances are needed. Measuring low resistance helps identify resistance elements that have increased above acceptable values. How you measure low resistances below one ohms? Most multimeters aren’t accurate below 1 ohm. Occasionally, you’ll need to measure electronic parts with very low resistances, such as wires, switches, current-sense resistors, →
The consumer market has adopted High-Definition Multimedia Interface (HDMI®) technology in TVs, projectors, and other multimedia devices, making HDMI a globally recognized interface. HDMI is a very popular video interface, but not everything have HDMI inputs or outputs. An HDMI converter is a device that converts an HDMI signal to another format — and vice →
My first 20 MHz oscilloscope still works but age shows. Bought this sometimes in 1990′s used, made maybe sometimes early 1980′s. I don’t have original manuals and I have not found much info on this on Internet. My first real oscilloscope: Iwatsu SS-5050. Served well for many years until a digital oscilloscope took it’s place →
Depends what you want. I’d go with a microcontroller for starts so you can change it programmatically. I’d bet someone has done it with an Arduino or Pi. Here are some links to interesting looking projects. Those circuits operate mostly at safe low voltages and control low power LEDs. The same ideas can be used →
A resistor is a resistor, a coil is a plain ol’ inductance, and a capacitor is a capacitor – or so you thought. Alas, life isn’t quite so trivial… There are non-ideal properties of real components. Capacitors have non-idealities that you should know about when designing electronics circuits. If you are building high frequency circuits →
Why??? They are so cheap these days compared to what they used to cost, why would you even bother to build your own fixtures? You will have more invested in parts and time then just buying them outright. I did build some disco lights in 1990′s. Nowadays you can buy many disco lights more cheaply →