The capacitor charging process
The capacitor charging process shows the variation of voltage and current in the capacitor over time, when it is connected to a DC voltage source
Dec 152018
Dec 102018
What is a sequential circuit? The main difference between a combinational circuit and a sequential circuit is that in the sequential circuit there is a feedback from one or more of the outputs to one or more of the inputs. Looking at the following diagram, you can see that the output of the OR gate is feedbacked to the input of the lower AND […]
Nov 262018
What is a Schottky Diode? The Schottky diode or Schottky Barrier Diode unlike the semiconductor diode that has a P-N juntion, has an N-Metal junction. These diodes are characterized by their switching speed and low voltage drop when they are forward biased (typically 0.25 to 0.4 volts). Its symbol is showed on the following diagram. This diode works allmost like the […]
Nov 262018
12 volt Power Supply using 7805
This 12 volt power supply circuit is simple and useful. Sometimes we need to get 12 VDC, but we only have 5 or 9 volts regulators (7805, 7809).
Nov 072018
This Electric Current Flow Indicator gives a visual indication that there is a current flow. Possible applications for this small circuit may be: a battery charger, a voltage power source, etc.
In order to achieve our objective we place 3 rectifier diodes in series, which in turn are in series with the load / battery.
Nov 012018
What is a Photodiode? Light Detector Diode.
Photodiode looks similar to the common LED, but it has a feature that makes it very special. It is a device that converts light into electric current.
Oct 312018
DC motor speed controller circuit using 555
This simple DC motor speed controller circuit, works with 12 volts and controls a DC motor using the 555 integrated circuit.
Oct 262018
Dual polarity variable voltage source
This voltage source allows for two independent voltage outputs. One positive and one negative with a maximum amplitude of +/- 15 volts, an a current up to 1.5 amps.
Oct 252018
A phototransistor is essentially the same as a common transistor, but it can work in two different ways:
– As a common transistor, using the base current (IB)
– As a phototransistor, using the light that illuminates this element and that acts as the base current. (IP).
Oct 192018
Counter-electromotive force or Back-electromotive force
The voltage of a DC motor is divided into a voltage in the windings resistance and a voltage called Counter-electromotive force
Oct 172018
DC Motor
A DC motor is composed of a stator and a rotor. In many small motors, the stator is composed of magnets. Larger motors have windings.
Oct 162018
Static Electricity – What it is?
Static electricity is static, since it is a current that is going nowhere. Both, DC and AC current flow in some direction, but estatic electricity does not.