Tagged Questions

6
votes
3answers
232 views

How does this circuit diagram work?

I don't understand this circuit diagram here, but I'm sure that you can help me out. I'll explain what I have figured out so far. EDIT: It's a metronome circuit. Sorry for being unclear about that. ...
3
votes
2answers
71 views

Heat Activated Alarm

I am working on a project in which I have to simulate a heat activated alarm. I have attached two images. One of which is a Proteus circuit image that i have made. When i start its simulation the ...
1
vote
2answers
137 views

How does the collector emitter relationship work with a transistor?

So, I'm not understanding how NPN transistors really work in this scenario. In this image, I have highlighted what I understand to be the collector and emmiter. My understanding is that power ...
1
vote
1answer
148 views

CMOS Inverter Voltage Transfer Function

So let's say I have a perfectly symmetrical Voltage transfer function curve for my CMOS inverter. The curve looks like this: The question is, how would this curve change if the size of the NMOS ...
1
vote
3answers
322 views

Any way to use N-channel mosfet in P-channel configuration?

In my application, I need the HIGH signal to turn a device OFF and vice versa. Clearly, this is P-mosfet configuration. However, I only N-mosfet on hand. Is there any clever way to utilize N-mosfet to ...
1
vote
4answers
288 views

Very Basic Electronics Question regarding current flow

This would be considered a basic electronics question that I should know (I've been all over the place with questions tonight and I apologize). But anyways using this circuit (It's a TTL SR latch) ...
0
votes
2answers
72 views

Voltage holder circuit configuration circuit

hi I didn't studies all the circuit configurations and also I'm a newbie to EE. My question is I need to design something like a voltage holder. The idea is two emitter followers. One is NPN one ...
3
votes
1answer
218 views

Why amplifiers (RC coupled) are based on voltage divider bias?

What actually determines the type of bias to be used for different practical applications. Also I do not get the point of using capacitors (coupling) for emitter current and high input resistance. If ...
0
votes
2answers
122 views

Transistor circuits: NOR and short

I've two short questions regarding circuits with a transistors or diodes: 1) The following circuit with two diodes: Does it produce an electrical short for B=1 (5V) and for B=0 there is V[out]=1? Is ...
1
vote
1answer
84 views

Does this product page contradict the corresponding datasheet?

I'm currently using N-channel MOSFET's my hobby circuit, and have had two go out on me. As a result, I'm studying them a little more and making sure I'm not doing anything that might harm them. On ...
2
votes
2answers
405 views

Latching power switch question

I have the following circuit (source: EDN): I understand the basic working principle of the circuit and it works fine when it is powered from a 1.5V source. But when I power the circuit from a 9V ...
4
votes
2answers
2k views

P-Channel MOSFET high side switch

I am trying to reduce the power dissipation of a P-Channel MOSFET high side switch. So my question is: is there any way in which this circuit can be modified so that the P-Channel MOSFET will ...
4
votes
2answers
333 views

Will this circuit work containing 2 transistors?

My gran keeps turning her internal light on in the car and then forgets to turn it off again. She has flattened the battery 5 times in the last few months. I've been looking at how integrated ...
6
votes
3answers
425 views

Controlling a current with another - home-made alternatives to the transistor?

I have a very basic understanding of how a BJT or a FET works, but I think I got the idea. They are awesome in all regards, except one: you can't make one at home without hot ovens and scary ...
4
votes
4answers
539 views

How to hack a walkie-talkie to light up LEDs when it receives a signal

Rookie circuit-bending question: I am trying to hack a walkie-talkie to light up some LEDs when it receives a signal. I figured the easiest thing to do would be to have the LEDs light in relation to ...
4
votes
1answer
202 views

Understanding a transistor configuration

I started watching this video series on a DIY lab power supply by Dave @ EEVBlog. On his video he's analyzing mostly simple constant current circuit. However, at the top of the circuit there's two ...
2
votes
1answer
553 views

In a BJ-Transistor, why do we need to bias the junctions?

I'm new to electronics and I'm kinda confused about transistors. In a bipolar junction transistor, why do we need to forward bias the emitter-base and reverse bias the collector-base?
9
votes
3answers
4k views

How do I know if which leg is the emitter or the collector? (Transistor)

I'm new to electronics and here's a newbie question that I would like to ask: How do I know if which leg is the emitter or the collector in a Transistor (For both PNP and NPN) using only an analog ...