# Tagged Questions

136 views

### Is it possible to provide power using (effectively) a single wire?

I come to this question after a few thoughts on capacitors. A capacitor essentially transfers (and stores) energy using an electric field through an insulator. The plates of a capacitor are not ...
103 views

### Using a 5v voltage regulator - Capacitors necessary? Better options?

I am very new to electronics. I am learning as I go, and I haven't quite found the answers I need; when it comes to programming, I'm not afraid of mistakes as they happen constantly. With electronics, ...
58 views

### What is the principle of active voltage balancing/equalizing device?

I am wondering about active voltage sharing devices. Their purpose is to equally divide voltages on slightly unequal super-capacitors. I found some papers like this, but it is too scientific. I want ...
99 views

### What formulas do I need to use to design a voltage regulator circuit for a zigbee radio?

I've written the code for my zigbee radios, but now I face the obstacle of getting them onto a carrier board to allow access to VCC, GND, TX, RX via a 4 wire connector. The supply voltage is 3.712 ...
116 views

### voltage regulators and capacitors

So I'm new to electronics and was looking at some Eagle schematics when I came across the following voltage regulator schematic: My question is: would it be possible to change the regulator to ...
412 views

### How to light an LED with very low voltage and low current?

The goal is to demonstrate, visually (with a light of some sort) that power is begin generated, albeit very, very small amounts of power. What kind of set up could I use to light up an LED (or any ...
169 views

### Voltage doubler or not?

I got a quick question! Is the circuit depicted in the link indeed a voltage doubler or is it just a bridge rectifier with smoothing capacitors?
631 views

### Simplest Way to step down the 220AC with more than 10% efficiency

Objective I want to design a tiny single packaged mains-powered temperature sensor. Possibly as a multi-chip module (MCM) on one small PCB board. Constraints The temperature sensor I plan to ...
131 views

### Voltage modulation with an LDO

I am trying to build a voltage modulation circuit using an adjustable LDO and a uC switchable resistor network (to provide different Vout levels). I need the circuit to provide 4.9, 5.1 and 5.3V at ...
467 views

### What is the lowest capacitor voltage rating that is safe to use?

I'm using a few Case R tantalum capacitors (10uF 6.3v) as bulk decoupling on the 3.3v power of a 100mbps Ethernet phy. I am also using 0.1uF ceramics closer to the pins. As usual, I'm terribly ...
600 views

### How can a capacitor in a disposable camera shock you?

The battery in a disposable camera is usually a single 1.5V AA battery. It charges a large capacitor. When the capacitor is fully charged, it will contain a voltage very close to 1.5V correct? If ...
865 views

### Why does an ideal capacitor give rise to a rectangular cyclic voltammogram (CV)?

Many scientists are interested in developing supercapacitors, which have electrolyte rather than solid dielectric between the charged plates. In the field of electrochemistry, cyclic voltammetry (CV) ...
319 views

### Can a capacitor act as a fuse?

I'm replacing the capacitor for a start motor that had previously burnt up. I'm new at this. I previously referenced the following questions about replacing caps with higher ratings than spec'd: High ...
199 views

### Capacitor discharge and 1/2 terminal voltage sources

I understand that this is really basics of electronics, but I would really appreciate if somebody clearly explained following question. So here is a small set of questions related to similar topic: ...
2k views

### Increase capacitor voltage rating by using multiple capacitors?

I'm trying to find a small 1000µf capacitor for my Arduino shield. The shield is a digital synthesizer that is powered by the Arduino's 5v regulated power. After discovering that the 5v supply from ...
174 views

### selecting voltage rate for capacitors

In my project I want to use some ceramic and electrolit caps, I will need the capacitors be at least 10V rated, but what will happen if I use much higher rated caps (just to make sure in case of ...
2k views

### Can I swap an electrolytic capacitor with one with a higher voltage?

I wish I knew more about this stuff, but alas I do not. I have a radial lead aluminum electrolytic capacitor (rated 470mF and 25v) that died on me. Can I swap it out with one rated at 35V, or do I ...
How would you solve for $V_x$ using node voltage method. I can solve this using $Q_{initial}=Q_{final}$, but I can't solve it using node voltage. Using node voltage I get ...