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12 votes

Could I power a corded device with batteries?

It will probably work for at least a little while. The issue is that a "1.5V" alkaline battery starts at around 1.6V and drops down to 1V over the life of the cell. The camera can probably ...
  • 5,458
8 votes
Accepted

What is the purpose of these resistors to ground in this EMC filter?

The resistors on the Cx and Cy capacitors are used for "DC voltage balance" thus ensuring that series capacitors are roughly sharing the same DC voltage i.e. they each have approximately ...
  • 413k
5 votes

Could I power a corded device with batteries?

Use whatever batteries you want. Use a SEPIC converter, it is a buck boost combined and set the output to what you want. It will automatically switch modes depending on the input output delta. Nice ...
  • 4,486
3 votes

Purpose of transistor "decoupling circuit"

I have no idea why it's there. Is it just to get a local 9.3V rail within the circuit? If so, why is it called a "decoupling circuit"? Are there any other reasons for that to be there[?] ...
2 votes

Can you run two motors of different hp off the same VFD independently?

Not really. The VFD is relying on the measurement of the current (magnitude and phase) that the motor pulls. If you have two motors, it gets nasty. Having said that, Rockwell says: "A variable ...
2 votes

Could I power a corded device with batteries?

Whether you can run the camera directly off batteries very much depends on the design of the camera. Unfortunately there may be no way to find out except trying it. Something with a nominally "...
  • 20.5k
2 votes

What is the purpose of adding series resistor to tantalum capacitors?

Older voltage regulator ICs were designed for use with aluminum electrolytic capacitors across the output. They can become unstable when a low ESR capacitor is placed across their output (such as a ...
2 votes

How is a short circuit useful at all for measuring the power transmitted through a transformer?

How is a short circuit useful at all for measuring the power transmitted through a transformer? By taking short circuit and open circuit measurements in a circuit, one can find impedances (including ...
2 votes
Accepted

Purpose of transistor "decoupling circuit"

Here's the specific part of the circuit: - It produces a reasonably regulated 9.3 volts from the 15 volt rail using 10 volts at the base. Because it's an emitter follower, the emitter will "...
  • 413k
1 vote

Is it possible to limit circuit and protect to 5 V whilst having a 5 V USB power in? I need around 1A current

A USB 2.0 host has a VBUS pin that is 5V but it is only required to supply 500mA, so that won't work for you. A USB-C host has a VBUS pin that is 5V and can supply up to 3A, so this can work for you. ...
  • 2,537
2 votes
Accepted

How to achieve 0.1 ms delay between an IC's different power rails without power-good signals?

The sequence of Power Rails 3V3, 1V8 and 1V0 is controlled by the RC networks at the inputs of each of the regulators' CE/MODE inputs (and the ON/OFF). They have a particular RC time constant to ...
  • 1,765
1 vote

What is the purpose of these resistors to ground in this EMC filter?

As far as I can see these power supplies can deliver 1200V and even "a few nF" could deliver quite a nasty shock at that voltage. Schaffner is being cautious, not wishing to surprise their ...
1 vote

Could I power a corded device with batteries?

Could I power a corded device with batteries? Yes. I did this with a set of desktop computer speakers. I started with a 9v battery, but it didn't last and was expensive. I ended up with a bank of 6 AA ...
1 vote

Could I power a corded device with batteries?

Even though the power supply is 12v 1A, the draw is likely a lot less, unless it has IR LEDs on it, and even then, only when its dark. The supply is common and probably just cheap in bulk. I might ...
1 vote

Could I power a corded device with batteries?

As an off the shelf option (ie not adding a voltage regulator into the mix), a box holding 10 batteries filled with NiMH rechargeable batteries would work much better. They stay close to 1.2V over ...
1 vote

Can you run two motors of different hp off the same VFD independently?

Some drives can select 2 or even 4 sets of parameters for differents motors (rated power, current and speed, inductance, resistance, overload limits, thermal models and others). You can select which ...
  • 962
1 vote

How to capture enough energy from a 433 MHz RF signal to activate a transistor?

It might be possible using a very high Q LC arrangement tuned to 433MHz such that it's voltage rises high enough to turn on an IGFET. However, any signal at that frequency might also trigger it. You ...
  • 13.1k
1 vote

How to capture enough energy from a 433 MHz RF signal to activate a transistor?

There's passively powered RFID tags, but they aren't LoRa devices, and it all works on much shorter distances than LoRa. It's not hard to calculate through Free Space Path Loss that remote power up of ...

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