Showing posts with label transistor. Show all posts
Showing posts with label transistor. Show all posts
Friday, October 31, 2014
Transistor Inverter circuit 12V to 220V 100W
This circuit power Inverter 100W, it easy and good ideas. When use the electric appliances that want 220V AC 50HZ, which have small-sized about 100Watt not exceed. By when you apply outside home, as a result have to have Mini power inverter about 100Watt, perform modify from work electricity forces of battery 12V give tall fair the work.
If you are New user electronics or want to economize or want to build electronics project use by oneself. I begs for to advise this circuit , because it uses , transistor number BC557 or the number replaces, perform oscillator generator. Then have power transistor 2N3055 numbers perform to drive coil transformer for converter voltage give tall go up 220V AC 50HZ at the electric power about 100 watt not exceed. When apply to transformer about 2A-3A.
Friday, October 17, 2014
Radio only 1 transistor without electricity
Experts and amateurs have been Experimenting with radios without batteries since the wireless communication started.
In many designs weve seen radios that operate without power, but all are known to use the diode 1N34. (Crystal Radio).
In many designs weve seen radios that operate without power, but all are known to use the diode 1N34. (Crystal Radio).
Although significant improvements have increased the sensitivity and selectivity of these system circuits, Performances were limited until new techniques have emerged.
Here we have the first transistor radio that works without batteries, it is powered by random electric fields are everywhere in the atmosphere.
These circuits are relatively cheap to manufacture, have more volume and better reception from the crystal radios.
This circuit is a medium wave receiver and attaches easily to frequencies from 500Khz to 11Mhz.
To get good results in the reception of radio stations, we should give great importance to the ground and the antenna.
To listen to distant and weak stations we have to use a battery 9volt parallel with the capacitor C4 with its positive side between R2 and C4.
The coils are in the frequency of 500-1500Khz is tight and closely wrapped.
The coils are in frequency of 1.5-11Mhz is more tighter and more closely wrapped.
This circuit is a medium wave receiver and attaches easily to frequencies from 500Khz to 11Mhz.
To get good results in the reception of radio stations, we should give great importance to the ground and the antenna.
To listen to distant and weak stations we have to use a battery 9volt parallel with the capacitor C4 with its positive side between R2 and C4.
The coils are in the frequency of 500-1500Khz is tight and closely wrapped.
The coils are in frequency of 1.5-11Mhz is more tighter and more closely wrapped.
Saturday, August 30, 2014
Bipolar Transistor Tester
This tester is primarily meant to test bipolar transistors. It can indicate the type of the transistor as well as identify its base, collector and emitter pins. The schema is very simple. The direction of current flow from the terminals of the transistor under test (TUT) is indicated by a pair of LEDs (green-red). An npn transistor produces a red-green-red glow, while a pnp transistor produces a green-red-green glow, depending on the test point that connects to the terminal of the transistor. Emitter and collector are differentiated by pressing pushbutton switch S1 that actually increases the supply voltage of the schema by about 5.1V.
At the heart of the schema is IC CD4069 (IC3), which oscillates and produces pulses required to test a pair of transistor leads for conduction in both the directions. Different combinations are selected by an arrangement of counter CD4040 (IC1) and bilateral switch CD4016 (IC2). Fig. 1 shows the schema of the bipolar transistor tester. A pair of LEDs is connected to each test point through which current flows in both the directions. Each LED corresponds to a particular direction. In this manner, both junctions of the transistor can be tested. The LEDs are arranged to indicate the type of the semiconductor across the p-n junction.
The counter is clocked by the AC generator built around gates N5 and N6. This makes the LEDs glow continuously for easy observation, revealing the direction of current flow between different test points. So if the red LED connected to certain point glows, it means that n-type of the junction is connected to that test point, and vice versa. Thusared-green-red glow indicates npn type of the transistor, while a green-red-green glow indicates a pnp transistor. From this observation, you can easily detect the base.
At the heart of the schema is IC CD4069 (IC3), which oscillates and produces pulses required to test a pair of transistor leads for conduction in both the directions. Different combinations are selected by an arrangement of counter CD4040 (IC1) and bilateral switch CD4016 (IC2). Fig. 1 shows the schema of the bipolar transistor tester. A pair of LEDs is connected to each test point through which current flows in both the directions. Each LED corresponds to a particular direction. In this manner, both junctions of the transistor can be tested. The LEDs are arranged to indicate the type of the semiconductor across the p-n junction.
The counter is clocked by the AC generator built around gates N5 and N6. This makes the LEDs glow continuously for easy observation, revealing the direction of current flow between different test points. So if the red LED connected to certain point glows, it means that n-type of the junction is connected to that test point, and vice versa. Thusared-green-red glow indicates npn type of the transistor, while a green-red-green glow indicates a pnp transistor. From this observation, you can easily detect the base.
Collector and emitter are differentiated based on the principle that the base-emitter junction breaks down under reverse bias much more easily than the base-collector junction. Thus under increased AC voltage, you can easily see that the emitter conducts more in the reverse direction (associated LED glows significantly) than the collector. Use of transparent or semi-transparent LEDs is recommended.
Adjust preset VR1 (2-mega-ohm) to get equal glow when any two test points are shorted. Unregulated 15V-18V is regulated by the zener-transistor combination to power the schema. The testing procedure is simple. Normally, the transistors can be plugged in any orientation as they come in a variety of possible arrangements of base, collector and emitter pins, such as CEB, BEC and CBE. Simply plug the TUT in the possible combinations of three points. A red-green-red glow means that it is npn transistor and the pin associated with green LED is base. To identify the emitter and collector, simply press switch S1 and observe green LEDs adjacent to already glowing red LEDs. The green LED glowing with a high intensity indicates the emitter side, while the low-intensity LED indicates the collector side.
Similarly, a green-red-green glow means that the transistor is pnp type and the pin associated with the red LED is the base. To identify the emitter and collector, simply press switch S1 and observe red LEDs associated with the already glowing green LEDs on the sides. The LED glowing with a high intensity indicates the emitter side, while the low-intensity LED indicates the collector side. Assemble the schema on a general-purpose PCB and enclose in a small box. Keep the preset knob in the middle. In order to make it easy to plug the TUT, you can increase the number of test points as shown in the authors prototype in Fig. 2
Source : Extreamcirciuts
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