1) Audio Power Amplifier
The following diagram is an audio power amplifier of 2x8.5W, the amplifier is stereophonic and I did a test with mp3 audio of a cell. To control the volume, I used the circuit shown below, which is a voltage divider with coupling capacitors and protection.
Hardware: IC LA4508, 2 Speakers 8 ohms, Diode DS1307, 2 Ceramic Capacitor 0.01,2 Electrolityc Capacitor 1000 uF, 2 Electrolityc Capacitor 220 uF, 2 Electrolityc Capacitor 100 uF, 2 R 160k, Ceramic Capacitor 100 nF, Ceramic Capacitor 1.5 nF, Pot 100k
2) VU meter
The VU meter circuit serves to observe the amplitude of an audio signal and using LEDs. Simply you have to feed the audio input and potentiometer serves to regulate the audio level LEDs.
Hardware:IC KA2284, 5 LEDs, Electrolityc Capacitor 10 uF, Electrolityc Capacitor 2.2 uF, R 56, Pot 10k
3) LDR Night Sensor
The LDR is a light sensing resistor, and when the LDR is in the presence of light, resistance is minimal. In this case the diagram is designed so that when there is no light then the LED is turned on. The residtance range and sensitivity of a photoresistor can substantially differ among dissimilar devices.
Hardware: Battery 5V, LDR, LED, R 330, R 1k, Pot 100k, Transistor 2N2222
4) AM Transmitter
The next AM transmitter has very low transmission power, so that is only didactic use and only can transmits to no more than five meters. Anyway you should verify the applicable standards. The two potentiometers are 10k and can adjust the transmission frequency of 540-1600 KHz
Hardware: IC 555, Ceramic Capacitor 1 nF, Electrolytic Capacitor 100 uF, Pot 10k
5) FM Transmitter
This FM transmitter has very low transmission power, so that is only didactic use and only can transmits to no more than five meters. Anyway you should verify the applicable standards. You should change the number of turns of the coil to have a good tune.
Hardware: Mic, Antenna, Transistors 2N2222, L 5 laps, Electrolytic Capacitors 10uF, Ceramic Capacitor .1, Variable Capacitor 5-60 pF, Ceramic Capacitor 1pF, 2 R 1k, R 10k, R 15k, R 6k8, R 4k7, R 2k2, R 220
An economical way to control the speed of an AC motor is using a dimmer. If you want to control the speed of a fan this is the circuit are you looking for.By changing the value of the potentiometer, amending reason the capacitor charge.This allows control can be the amount of current flowing to the load and so the power therein, is to be consumed.
7) Testing A TRIAC
To test a TRIAC simply we have to place as shown in the image and press the switch. If the lamp is turn on this means that is in good condition.
Hardware: R - 1k, Push Button, Lamp
8) Testing A Zener
To test the Zener simply we have to place as shown in the image and measure the voltage. If the voltage of operation is correct then it's in good condition the Zener.
Hardware: Battery 5V, Ceramic capacitor .68 uF, Electrolytic capacitor 1 uF, Electrolytic capacitor 470 uF, R 1M, R 1k, R 10k, Transistor BC547, Diode 1N4004
9) Testing A Mosfet
To test the N channel Mosfet simply we have to place as shown in the image and press the push button. If the LED turn on it means that the Mosfet is in good condition.
Hardware: Battery 5V, Push Button, R 1k, R 470, LED
10) Testing An Optocoupler
To test an Optocoupler simply we have to place as shown in the image and press the button. If the LED turn on it means that the IC is in good condition.
Hardware: Battery 5V, Switch, Transistor 2N2222, Push Button, 2 R 330, LED
© 2017 Guillermo Perez Guillen