One output power source

I wish to create two circuits that reflect one power source output similar to the "VCC" symbol at How can I do this in Circuit Lab where the closest symbol I can find is the two output "Voltage Source"? Thank you.

October 19, 2021

I have been told that Vcc was derived from "Constant Voltage at the Collector", which was the norm for early IC chips to be powered through a NPN's collector pin. Some OpAmp have a Vcc and a Vee pin, the Vcc being for the most positive voltage alimentation and Vee, the most negative voltage alimentation (traditionally, at an emitter pin of an NPN). That convention is not universal, though.

You should be able to reach your goal by using a DC voltage source set at the required voltage.

by vanderghast
October 20, 2021

Thank you for the reply, vanderghast; I'm just confused what to do with the negative pole of the "Voltage Source" - can I just affix it to signal "GND (G)" and ignore it?

October 20, 2021

A Voltage Source can be a battery for constant voltage, or from an electrical wall outlet from the domestic distribution for an alternative voltage source.

In an isolated circuit (like a cell phone, or a disconnected laptop, handheld radio, electronic calculator, electronic watch, ... ), the "ground" is often the point where the voltage is at its minimum.

For an isolated circuit with a battery, unless otherwise specified, the + pin of the battery is Vcc and the - pin of the battery is the ground.

by vanderghast
October 20, 2021

"ground" or "gnd" is kind of a loose term. In an engineering design office the convention may be used that gnd is traceable to an actual ground rod driven into the earth. If it is simply a junction point where the voltage is defined as zero it is called "common" or com. Less chance of confusion that way.

by Foxx
October 21, 2021

Thank you vanderghast and Foxx. After each of your replies, I proceeded to craft one of the two zener voltage regulator circuits I desired, tying the negative pole of the "Voltage Source" directly to "GND (G)." When finished, I inserted the "Digital Probe" throughout the circuit and clocked "Simulate." Unfortunately, no wire - not even the positive "Voltage Source" wire returned a single voltage; "Run DC Solver" failed to execute and auto-shutdown. Wishing to save my work so I could add it to dedicated thread to seek feedback, I encountered a "Cannot save without an active CircuitLab membership" prompt. Now I'm simply out of luck altogether.

To share simply, I have two separate zener voltage regulator circuits I am seeking an educated mind to either (1) confirm as being equivalent or (2) provide guidance on how to make them equivalent. Alas, I cannot find ANYWHERE online - including MIT's "free" online question submission forum - in which an engineer will assist. If anyone here can refer me to another online resource that will help, my entire work team would be most grateful. Thank you.

October 21, 2021

1 Answer

Answer by vanderghast

Note that the source, here V1, must supply a voltage greater than the Zener voltage, else, the Zener diode will stop the current through it.

Technically, to avoid excessive lost in heat through the resistors, you could design them to allow just a little bit more than 1 mA through them. As example, it would be better, for R1, to obey: 12 volt = 5.1 volt (zener) + R1 * 0.001 amp, giving R1 less or equal to 6.1 kohm.

+1 vote
by vanderghast
October 21, 2021

Typo: it is 6.9 kohm, not 6.1.

by vanderghast
October 21, 2021

I appreciate your motivation and effort on this subject, vanderghast; however, I literally have two separate zener voltage regulatory circuits (built using Electronics Workbench/National Instruments multiSIM 8 software) I am seeking feedback on. Thanks to your guidance, I can build both on Circuit Lab; unfortunately, I cannot save them to attach in a thread for outside review. If no additional ideas populate here, this, too, will become a lost opportunity to receiving the expertise my team is requesting.

October 24, 2021

I have used Circuit Lab for some time now and found it is well worth the cost even for hobby plus some work you might call "pro bono". I only wish it had been available when I made living at this stuff. Based on my experience it would be well worth while for you to get a membership.

by Foxx
October 25, 2021

If I were remaining in my current position long-term - true - I'd find value in a resource like this. However, I'll be transitioning out in less than a year; where I'd headed won't have need for creating circuit simulations.

This zener question is the only doubt we have on our team - once we resolve it, we'll be squared away.

October 25, 2021

Your Answer

You must log in or create an account (free!) to answer a question.

Log in Create an account

Go Ad-Free. Activate your CircuitLab membership. No more ads. Save unlimited circuits. Run unlimited simulations.

Search Questions & Answers

Ask a Question

Anyone can ask a question.

Did you already search (see above) to see if a similar question has already been answered? If you can't find the answer, you may ask a question.

About This Site

CircuitLab's Q&A site is a FREE questions and answers forum for electronics and electrical engineering students, hobbyists, and professionals.

We encourage you to use our built-in schematic & simulation software to add more detail to your questions and answers.

Acceptable Questions:

  • Concept or theory questions
  • Practical engineering questions
  • “Homework” questions
  • Software/hardware intersection
  • Best practices
  • Design choices & component selection
  • Troubleshooting

Unacceptable Questions:

  • Non-English language content
  • Non-question discussion
  • Non-electronics questions
  • Vendor-specific topics
  • Pure software questions
  • CircuitLab software support

Please respect that there are both seasoned experts and total newbies here: please be nice, be constructive, and be specific!

About CircuitLab

CircuitLab is an in-browser schematic capture and circuit simulation software tool to help you rapidly design and analyze analog and digital electronics systems.