Test of ganacia for transistors
With the armed one of this circuit we will be able to analyze the state of transistors and semiconductors generally, the same will indicate the gain to us of a transistor with approach enough.
Way of use: The indication of the gain of the transistor under test is indicated with the ignition of a diode LED, if in the first scale the LED ignites that indicates gain of 250 then we will be able to affirm that this one is 250 superior to and inferior to 300, if it ignites the LED that indicates a gain of 500 then we will have to happen to the second scale to see if the gain is not superior (for example 700 or 800).
The change of category, change of status takes control of double switch S2/A - S2/S3, being in the scale that indicates a beta between 50 and 500 if they do not cortocircuitan R1 - R4 and in the scale that a beta between 100 and 1000 indicates when R1 and R4 are cortocircuiten.
With P1 and P2 the currents adjust to apply on approval in the bases of the transistors. For the adjustment of trimpots uA in CC can be used to téster in the scale of 200, to feed the probador and to connect the negative end to the tip “and” and the positive end to the “B” of transistor NPN and to turn the P1 potentiometer until obtaining a approximately 10 measurement of uA; soon to place the negative end to the terminal “B” and the positive one to the “E” of transistor PNP and to turn trimpot P2 until obtaining a current of 1 uA.
If we wished to prove a transistor of which we do not know which are legs EBC we will begin to insert the terminals at random and later to change them until obtaining a combination that makes ignite led´s. If we did not manage to make ignite any LED we will have to change to the other terminals, that is to say that we are proving if it in terminals PNP we will happen vice versa to the NPN or, and if this way we did not obtain either that some then LED ignites to this it will indicate us situation that the transistor has a gain inferior to 50 or that is burned.
Finally, if we are proving a transistor NPN in the terminals of test PNP will not ignite no LED.
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List of components |
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| Resistance | Capacitores | Semiconductors | Several |
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- R1, R2, R3, R4 - 220 ohms - R5, R6 - 33 K ohms - R7, R9, R13, R14, R16 - 47 K ohms - R8, R11, R12, R15 - 100 K ohms - R10 - 12 K ohms - P1, P2 - 50 Potentiometers K ohms |
- C1, C2 - 47 nF - C3, C4 - 100 nF - C5 - 100 uF, 25 V |
- L1 to L10 - Diodes leds 5 mm, Red - CI1 - LM 358 - CI2 - LM 3914 - Q1 - Transistor PNP BC527 - Q2 - Transistor NPN BC537 - D1, D2, D3, D4 - Diodes 1n4148 |
- S1 - Interrupting simple - S2, S3 - Investing simple |
