It will probably take me some time to look up all terms and try to understand the explanations :) So please bear with me. One LED should be ON while the switch is pressed, then should switch to the other if pressed.Įdit 2: Thank you for all your amazing additions to the post. Some basic Idea, without any resistors (since they are part of my problem: I con't find out, where to place them and how strong.) Placed on my breadboard to get started with LEDs. Thanks für input on this very confusing matter. I am too embarrassed to show any of these noob tries, and just want to ask you guys for Ideas how to approach that problem.Īm I going a completely wrong way with this? Then, PNP transistors use a small base current and a negative base voltage to control a much larger emitter-collector current. But i do not seem to be able to have either the NPN or PNP transistor not be triggered to a degree somehow. The main difference between the two types of transistors is that holes are the more important carriers for PNP transistors, whereas electrons are the important carriers for NPN transistors. Depending on what is added to the silicon, it will be either N-type or P-type. A bipolar junction transistor is made up of three pieces of silicon. The practical result is the direction of current flow. How to distinguish PNP and NPN transistors - Electrical Engineering Stack Exchange How to distinguish PNP and NPN transistors Ask Question Asked 7 years, 2 months ago Modified 5 years, 2 months ago Viewed 7k times 4 I need to know how to distinguish between an NPN transistor and a PNP transistor. So far, I have tried a lot to get it work somehow. NPN and PNP refer to the arrangement of the pieces that make up the transister. If the GPIO pin goes HIGH or LOW, switch trough either transistor. Must have (conventional) current flowing into emitter (top) Are the above two conditions accurate for each And Are there any other requirements to turn on a NPN/PNP transistor transistors. Electron density is less, only 5 of holes enter the base with the electrons which show up to base current I B.Base current is 5 of I B. I thought about using an NPN and PNP transistor, tying up the base and collector/emitter to 5v power supply. Must have (conventional) current flowing into collector (top) PNP. Working: The electrons are majority charge carriers in P-type semiconductors and are beaten back by the positive terminal of the battery V EE in emitter current I E. Some guys might say "P to N to P, that's the same as N to P to N ? (NO it's not, as the N becomes the substrate, instead of P).I want to toggle between 2 devices using one GPIO 3.3v pin and powering them with 5v. but are still percived by "the old hands" in designing power sections, as being a "poor transistor" simply by design. After comparing the spec sheets online and doing a little bit of googling, I found that PNP transistor 2N3906s characteristics and specs seem to fit pretty well with BC559 and BC548 fits fairly well with 2N3904s. The origins of Transisitors, PNP was a very easy latice structure to acheive, the P doped portion then the N, then another P doped section, "Tada!" PNP, HOWEVER, NPN, ain't so easy to make (not then, and still is harder than pnp now) see, the bonding junction wants to be P biased, therefor the process we must use is WAY more complex to build an N bonding junction (Something to do with atomic latice or something) anyhow, so back in the beginnings PNP prevailed simply because they where a cheaper transistor to mass produce (VHS vs BETAMAX ?) since these where what everybody used back in those days, the progress continued on the prefection of the PNP junction, because NPN is needed in medical equipment (don't go there) the progress on manufacture of them has kept pace to a lesser degree, but NPN units rivial the cost of their PNP counterparts nowdays. My problem is I couldnt find the two transistors, NPN BC548 and PNP BC559 at any of my nearby Radio Shacks. However, Can I get my 2 cents in on part of the original question Os transistores PNP so constitudos por 2 camadas de material P emparelhando uma camada de material N, enquanto os transistores NPN so compostos de 2 camadas de material N que embalam 1 camada de material P. I aggree, complementary symmetry is NOT perfect, because the comp.
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