Videos

1403

Operational Amplifier LM324 and super microphone circuit

Afroman goes over the basics of how to use an operational amplifier to amplify tiny voltages, and builds a circuit to listen to very faint sounds with a microphone.

For more information about amplifiers, Google “inverting amplifier” “non-inverting amplifier” “instrumentation amplifier” “class A amplifier” “class B amplifier” “class AB amplifier” and that should give you a lot to chew on.

1393

Video tutorial Electrical Transformer + AC to DC conversion

Afroman covers the basics of how transformers work, where to shop for step down mains transformers, and how to wire one up to mains voltages without killing yourself. European and North American wiring is discussed. He finishes up with a quick example of AC to DC conversion in an unregulated dual rail power supply.
A transformer is a device that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer’s coils. A varying current in the first or primary winding creates a varying magnetic flux in the transformer’s core and thus a varying magnetic field through the secondary winding. This varying magnetic field induces a varying electromotive force (EMF), or “voltage”, in the secondary winding. This effect is called mutual induction.

1414

Making double layer PCBs at home – video tutorial

Small tutorial, how to make PCBs at home, using photoresist methode.

1409

LM317 Adjustable Voltage Regulator video Tutorial

A tutorial on the LM317 voltage regulator. Shows you how to make a 1.25 to 25V adjustable voltage supply, or choose any other output voltage you want. An example of a fan speed controller is shown.

The LM117 series of adjustable 3-terminal positive voltage regulators is capable of supplying in excess of 1.5A over a 1.2V to 37V output range. They are exceptionally easy to use and require only two external resistors to set the output voltage. Further, both line and load regulation are better than standard fixed regulators. Also, the LM117 is packaged in standard transistor packages which are easily mounted and handled.

In addition to higher performance than fixed regulators, the LM117 series offers full overload protection available only in IC’s. Included on the chip are current limit, thermal overload protection and safe area protection. All overload protection circuitry remains fully functional even if the adjustment terminal is disconnected.

Normally, no capacitors are needed unless the device is situated more than 6 inches from the input filter capacitors in which case an input bypass is needed. An optional output capacitor can be added to improve transient response. The adjustment terminal can be bypassed to achieve very high ripple rejection ratios which are difficult to achieve with standard 3-terminal regulators.

LM317 Adjustable Voltage Regulator video Tutorial - how to make a 1.25 to 25V adjustable voltage supply

 Datasheets LM317

1396

Video turorial Voltage regulator tutorial & USB gadget charger circuit

This video covers the basics of linear voltage regulators – what they do, how to wire them up, and where to find them. Then I give a basic example of how to build a 5V supply that can be used to power USB powered gadgets.
The LM341 and LM78MXX series of three-terminal positive voltage regulators employ built-in current limiting, thermal shutdown, and safe-operating area protection which makes them virtually immune to damage from output overloads.

With adequate heatsinking, they can deliver in excess of 0.5A output current. Typical applications would include local (on-card) regulators which can eliminate the noise and degraded performance associated with single-point regulation.

1406

Voltage divider video tutorial – Voltages dividers and how to build one

This video shows the basics of voltages dividers and how to build one. Power consumption considerations and equivalent series resistance issues are also discussed.

In electronics, a voltage divider (also known as a potential divider) is a simple linear circuit that produces an output voltage (Vout) that is a fraction of its input voltage (Vin). Voltage division refers to the partitioning of a voltage among the components of the divider.

The formula governing a voltage divider is similar to that for a current divider, but the ratio describing voltage division places the selected impedance in the numerator, unlike current division where it is the unselected components that enter the numerator.

1390

Video tutorial Multimeter – how to use a multimeter to measure voltage, current, resistance and continuity

Afroman shows you what to look for in a multimeter, and how to use a multimeter to measure voltage, current, resistance and continuity.

A multimeter or a multitester, also known as a or VOM (Volt-Ohm meter), is an electronic measuring instrument that combines several measurement functions in one unit. A typical multimeter may include features such as the ability to measure voltage, current and resistance. Multimeters may use analog or digital circuits—analog multimeters (AMM) and digital multimeters (often abbreviated DMM or DVOM.) Analog instruments are usually based on a microammeter whose pointer moves over a scale calibration for all the different measurements that can be made; digital instruments usually display digits, but may display a bar of a length proportional to the quantity measured.

1386

Video tutorial – Diode Tutorial & How to build an AC to DC power supply

This video covers the basics of diodes, bridge rectifiers, and how to build simple unregulated AC to DC power supplies than can handle a few mA up to several Amps.

Aspect Diode and Symbol
Diode and Symbol
1383

Video tutorial How To Test A Bridge Rectifier With A Digital Multimeter DMM

A Short & Easy Test To Check If A Bridge Rectifiers Shorted or Not!!Hope This Helps Someone Out There.

A bridge rectifier makes use of four diodes in a bridge arrangement to achieve full-wave rectification. This is a widely used configuration, both with individual diodes wired as shown and with single component bridges where the diode bridge is wired internally.

Rectifier bridge Aspect
1379

How to build the best homemade hdtv antenna – video tutorial

This is how to build a homemade TV antenna so that you can catch FREE HDTV. All you need is some copper wire, screws, washers, a piece of wood and a balum.
How to build the best hdtv antenna - video tutorial

Material list for HDTV homemade Diy Antenna

  •  10 Feet of Copper Wire
  • 6 Washers
  • 6 Wood screws
  •  2-3 foot piece of Wood
  • 1 Balum or Transformer
  • Something that can cut the Wire
  • Drill / Screwdriver
  • Tape Measure
  • Sharpie

Schematics for HDTV homemade Diy Antenna