# Tag Info

### Is there ever any reason to prefer 5% tolerance resistors over 1%?

Although answered in several ways here correct, it boils down to the the type of circuit. If one is building an audio amplifier, some looseness is good, and the ceramics are more forgivable under load....
1 vote

### What should my resistor wattage be to run a LED on 240VAC?

I actually found this exact thing in an old kettle I pulled apart they are using a 46 kΩ resistor in series with a standard blue LED, in series with a diode the resistor looks about 8 W capacity, ...
1 vote

### Frequency compensation circuit

Your circuit is a high pass filter. The time constant of the circuit can be found by looking at the circuit from the capacitor’s point of view. The capacitor sees R an Rc in parallel. The time ...
• 1,600
Accepted

### Adding Resistor to Match Power Draw for Fan Replacement

Your calculations are correct: If you want to draw the difference in specified currents between the two fans (0.23 - 0.06 =) 0.17 A at 12 V then the resistor should be approximately 70 Ω. And it would ...
• 17.9k

### How does this simple circuit work if the diodes are replaced by LEDs?

How does this simple circuit work if the diodes are replaced by LEDs? It doesn't work for its intended purpose. I imagine you want to retain the diode functionality, but add indication of which ...
1 vote

### How does this simple circuit work if the diodes are replaced by LEDs?

As already mentioned the drop over a LED is too high. Also the current is very limited. Schottkys support much higher currents. This is how I would do it (for a low power application):
• 624

### How does this simple circuit work if the diodes are replaced by LEDs?

Short answer: as shown, this won't work hardly at all with LEDs swapped in. Why? LEDs have a much higher forward voltage drop (Vf) than normal diodes, somewhere between 1.2 and 3.5V depending on ...
• 54.9k

### How does this simple circuit work if the diodes are replaced by LEDs?

If both voltage sources are present, then D9 is in reverse bias so no current flows and the diode is not illuminated. I don't recommend this circuit since you are limited to the current of the diodes, ...
• 20.2k

Two ten watt resistors, in series or parallel, can handle 20 W easily. A metering problem with high voltage might indicate that a different technology would be preferable; there are electrostatic ...
• 7,683
Accepted

Check the datasheet. A common rating on resistors is a five-second overload at some multiple of rated power (usually 5x). Satisfactory performance is usually gauged by resistance being within ...
• 39.2k

You can run the resistor above its DC rating if the datasheet provides information saying you can do it. Typically, this would be a graph, a table, or a statement specifying various combinations of ...
• 12.4k

Resistors can generally be run briefly at a higher power than their continuous rating. However, most resistors are not specified for that type of operation, so it's not advised. Film type resistors ...
• 169k

### What happen if both sides of LED connected to positive?

It does nothing, in any case. It's the opposite of a short circuit. You connected both sides to the same potential, so there's no potential difference across the LED and no current flow. Adding a ...
• 7,637

### What happen if both sides of LED connected to positive?

A1) No, nothing happens. The result is exactly the same as connectig the two LED terminals together with a piece of wire or screwdriver. Sure the LED terminals are shorted, but the LED does not care, ...
• 158k
1 vote

### Why does a 230V 16A socket supply only the needed current to loads?

If I connect a 150W laptop charger to a socket that supplies at home 16A 230V, it will only draw the necessary amperage needed for the laptop charger at 230V. Why? The definition of electrical power ...
• 5,317

### Why does a 230V 16A socket supply only the needed current to loads?

Your socket rated at 16A does not know how many hundred or thousand amps are available from your electricity provider and it also does not know how much your laptop needs for charging. If you connect ...
• 158k
1 vote
Accepted

### RC series analysis with H parameters model

Given \\$\left[\begin{matrix}v_1\\i_2\end{matrix}\vphantom{\begin{matrix}R\\sC\end{matrix}}\right]=\left[\begin{matrix}h_{11}&h_{12}\\h_{21}&h_{22}\end{matrix}\right]\left[\begin{matrix}i_1\\...
• 11.1k