• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Daily Review!

Not open for further replies.


New Member
I had an idea and i hope you all will participate. Many of us are beginners and many of us have a history of electronics and often need a review of things we learned in the past. It is said that everyone learns something new every day. To the point...

I propose that we use this thread as a review to all the therory we have learned in the past and all the theror we are learning today, both as beginners and as electronics gurus.

This thread can be thought of as a FAQ thread but not limited to...

Post Things such as:

  • Formulas

Every time your learn something new or old about electronics share it here. This will give members who may not any reason to ask a certain question to read and keep their mind fresh with basic things such as definitions and acronyms.

If it catches on it could get sticky'ed


New Member
Topic: Soldering

Solder which is made up of a combination of metals will melt between 180 to 200 degrees celcius. Electronic grade solder is usually made up of 63 percent TIN and 37 percent LEAD

Also having a higher power rating on a soldering iron does not mean the iron will get hotter. A higher power rating simply means that the iron will replace the disipated heat faster.

Does your brain want to know more about soldering....Then Check out this site http://www.epanorama.net/links/basics.html#soldering


Topic:Current, Voltage and Resistance

The ability of an energy source (e.g a battery) to produce a current within a conductor is a measure of its electromotive force (e.m.f). Whenever an e.m.f is applied to a circuit a potential difference (p.d) exists. Both e.m.f and p.d are measured in volts (V). In many practical circuits there is only one e.m.f present (the battery or supply) however, a p.d. will be developed across each component in the circuit.

For any conductor, the current flowing is directly proportional to the e.m.f applied. The current flowing will also be dependent on the physical diamensions (length and cross-sectional area) and material of which the conductor is composed. The amount of current that will flow in a conductor when a given e.m.f is applied is inversely proportional to its resistance. Resistance, therefore, may be thought of a an opposition to current flow; the higher the resistance the lower the current that will flow (assuming that the applied e.m.f remains constant)


New Member
Squintz said:
Topic: Current Flow

The following Animation will show how electrons flow from the negative terminal of a battery to the positive side. Demonstrating that Current flows from negative to positive.

Hehheh...at least you realize it's not the electrons themselves that yield electricity so-to-speak. I love how every highschool science book defines electricity incorrectly, "Electricity is the flow of electrons." No...it is the flow of the ABSENCE of electrons.
Not open for further replies.

Latest threads

EE World Online Articles