I am working on a project about logic control. This is extremely easy by an Arduino, however I want to make it more complicated by designing it with BJT's. I am using an Arduino too, but it could be exchanged by simple buttons wired to logic power.
I have drawn the schematic and the truth table.
I would like to hear from you whether it would work and whether the resistor values have been chosen properly for the BJT's chosen.
Note.- The current load of each coil is about 500mA at 36V.
The logic looks right, looking at it as a matter of ideal transistors.
Whether the biasing is appropriate for any or every condition I won't speculate.
But BJT is what they are. It helps to differentiate them from MOSFET, which is also a "transistor". Just calling them transistors is like calling your pet dog "Dog", or saying you drive a "Car GTi".
When I went to school the term "transistor" implied the bipolar junction sort. If the matter was FETs in some general sense or MOSFETs, JFETs,... or whatever else then that was made clear. But still, it would be about "the FET's this" or "the FET's that".
It was never "BJT" (bee-jay-tee), absolutely never.
[It's odd. That's why our friend, robtillaart, asked "What are BJTs"?]
It was the same back when I was at college too, but times have moved on. Back then MOSFETS were the exception, not the rule. Now it is far more common to talk about MOSFETS (thanks to CMOS) than BJTs. These days you have to be more explicit when you talk about transistors, because it's not obvious which you mean any more.
Of course, they do. This issue is like life itself. You can be a professional and call to stuff by its proper name or just say something to describe it. I am actually an industrial engineer and my instructors used to call everything in a proper way.
robtillaart:
Why don't you make the circuit in such way that every pin controls one coil?
would be easier to program I think?
For sure, it would be much easier. That's the key. I want to make "the logic by BJTs", as the title says. I really like designing new circuits and see them working, this is the reason to try this one. A circuit like this wouldn't make sense at all in nowadays real life, with a widely much better components like uCs ans MOSFETs.
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