Showing posts with label transistor. Show all posts
Showing posts with label transistor. Show all posts
Tuesday, October 28, 2014
Transistor Checker with 555 Timer 4027IC
This regular circuit has helped me prohibited on many occasions. It is able to check transistors, inside the circuit, down to 40 ohms across the radio dish-foot otherwise base-emitter junctions. It can in addition check the output power transistors on amplifier circuits. Circuit company is because follows. The 555 timer ( IC1 ) is usual up as a 12hz multi vibrator. The output on pin 3 drives the 4027 flip-dud ( IC2). This flip-flop divides the input frequency by two and delivers complementary voltage outputs to pin 15 and 14. The outputs are connected to LED1 and LED2 through the current limiting resistor R3.
The LEDs are arranged so to facilitate what time the polarity across the circuit is lone way single one LED force light and what time the polarity reverses the other LED will light, therefore while rebuff transistor is connected to the tester the LEDs will alternately flicker. The IC2 outputs are too connected to resistors R4 and R5 with the junction of these two resistors connected to the immoral of the transistor being tested. With a proficient transistor connected to the tester, the transistor yearn for circle on and crop a passing across the LED duo. If a good NPN transistor is connected next LED1 will burst by itself and if a good PNP transistor is connected then LED2 will flash by itself. If the transistor is initiate both LEDs force flash and if the transistor is shorted at that moment neither LED will flash.
Wednesday, October 22, 2014
2 Transistor Line Follower Robot
Make a line follower robot can be done with two transistors. Line Follower Robot series is one of the two transistors contor robot line follower circuit is in Bagun with two NPN transistor and the motor driver as well as processing of sensor signals.
In the circuit of line follower robot consists of two parts of the same, only different functions for the motor driver the right and left. Sensor circuit of line follower robot uses the LDR and LED. LDR sensor sensitivity can be set with the VR 10 is mounted in series with the LDR. For more details, see the following figure.
In the circuit of line follower robot consists of two parts of the same, only different functions for the motor driver the right and left. Sensor circuit of line follower robot uses the LDR and LED. LDR sensor sensitivity can be set with the VR 10 is mounted in series with the LDR. For more details, see the following figure.
Line Follower Robot series 2 Transistor
The working principle of the motor driver circuit between the right and left together, when the LDR get the reflection of light from the LED LDR resistance will decrease and make the transistor saturation and motor gets supply and rotates so that the robot moves forward. So at the moment is not the case then the motor did not get a supply, for example, only one sensor is exposed line and make the LDR did not receive the reflected light is then Motr in the stationary and the other motor rotates and makes the LDR are back in the reflection of light and the robot moves forward again.
Sunday, October 5, 2014
Latest Transistor In Circuit Checker latest
This simple circuit has helped me out on many occasions. It is able to check transistors, in the circuit, down to 40 ohms across the collector-base or base-emitter junctions. It can also check the output power transistors on amplifier circuits.
Circuit operation is as follows. The 555 timer ( IC1 ) is set up as a 12hz multi vibrator. The output on pin 3 drives the 4027 flip-flop ( IC2). This flip-flop divides the input frequency by two and delivers complementary voltage outputs to pin 15 and 14. The outputs are connected to LED1 and LED2 through the current limiting resistor R3. The LED’s are arranged so that when the polarity across the circuit is one way only one LED will light and when the polarity reverses the other LED will light, therefore when no transistor is connected to the tester the LED’s will alternately flash. The IC2 outputs are also connected to resistors R4 and R5 with the junction of these two resistors connected to the base of the transistor being tested. With a good transistor connected to the tester, the transistor will turn on and produce a short across the LED pair. If a good NPN transistor is connected then LED1 will flash by itself and if a good PNP transistor is connected then LED2 will flash by itself. If the transistor is open both LED’s will flash and if the transistor is shorted then neither LED will flash.
Thursday, October 2, 2014
Simple Transistor Hfe Tester Circuit Diagram Using IC 741
- P1 is used to set a reference voltage derived from voltage UXY UD1 (or D2 for a PNP transistor). This means that l the setting of the potentiometer is directly proportional to the hpp; of the transistor under test and is independent of supply voltage.
- The voltage across R2 and the voltage set with P1 are compared by lC1 which is connected as a comparator. Potentiometer P1 is now set so that the LED at the output of the op-amp just lights or is just dimmed.
- This hfe tester is interesting because of its simplicity and because it enables the B of both PNP and NPN transistors to be measured.
- At this setting the voltage across the potentiometer is equal to the voltage across R2. Switch S1 is used to switch from NPN to PNP (or vice versa) by reversing the polarity of voltage UXY.
- LEDs D3 and D4 in the supply lines ensure that the input voltages to be measured are within the common mode range of the opamp used.
- Furthermore the measurement is independent of the supply voltage of the tester. As the diagram shows, the base current of the transistor under test travels via R1. Its base current IB is thus equal to The voltage drop across the collector resistor is hfe x IB x R2.
Monday, September 15, 2014
In Circuit Transistor Checker
This simple schema has helped me out on many occasions. It is able to check transistors, in the schema, down to 40 ohms across the collector-base or base-emitter junctions. It can also check the output power transistors on amplifier diagram. Circuit operation is as follows. The 555 timer ( IC1 ) is set up as a 12hz multi vibrator. The output on pin 3 drives the 4027 flip-flop ( IC2). This flip-flop divides the input frequency by two and delivers complementary voltage outputs to pin 15 and 14. The outputs are connected to LED1 and LED2 through the current limiting resistor R3.
Circuit Diagram
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