# What does it mean when the current is constant?

## What does it mean when the current is constant?

A constant current (steady current, time-independent current, stationary current) is a type of direct current (DC) that does not change its intensity with time.

## What is constant current vs constant voltage?

Constant voltage luminaires require a steady voltage to be supplied from the driver eg 12 or 24 Volts. For these lights the voltage is fixed by the driver but the current may vary. Constant current luminaires require a constant current to be supplied from the driver eg 350mA or 700mA (milli-amps).

What is constant current dimming?

Constant current reduction, also referred to as analog dimming, is the relatively simple method of controlling the amount of current supplied to the LED(s). Full LED brightness occurs when the maximum amount of allotted current is provided to the LED(s), and dimming occurs when the current is reduced.

### What is constant current used for?

Constant current drivers are designed for LEDs that require a fixed output current and a range of voltages. Constant current drivers usually list their specifications on the device, with only one output current rating and a range of voltages that vary based on the wattage of the LED.

### What is Ohm’s law state?

Ohm’s law states that the current through a conductor is proportional to the voltage across the conductor. V=IR where V is the voltage across the conductor and I is the current flowing through it.

First thing to address is what is D.C. Steady State. Basically, all that means is that the circuit has been active/running for a long time. At DC steady state, the current no longer changes (it reaches a maximum through an inductor), so di/dt = 0 so the voltage is 0.

## Do leds need constant voltage?

Constant voltage drivers used in LED lighting applications mainly usually have an output voltage of 12V or 24V DC. The main type of LED lighting that uses constant voltage is LED strip but some LED lamps and LED downlights also require constant voltage so it is important to check.

## Is constant voltage DC?

Constant voltage drivers are designed for a single direct current (DC) output voltage. The driver will always maintain a constant voltage no matter what kind of current load is put on it.

What is PWM dimming?

Pulse-width modulation (PWM) is a common type of dimming used to adjust the current in white-LED driver devices. PWM dimming takes a rectangle waveform with variable positive duty cycle (D) and adjusts the LED current proportionally.

### What is analog dimming?

Analog dimming is the adjustment of the average continuous LED current. Analog dimming is typically the simplest dimming method to implement. To implement it, you simply adjust the analog voltage on the current adjust pin on an LED driver, which is used as a reference to adjust the output LED current.

### Can a camera draw 300mA from a 500mA power supply?

I didn’t think it would. If a camera draws 300ma on a 500ma supply, it will draw exactly the same 300ma from a 1a supply, or a 2a supply… A power supply that can provide more amperage will just have extra unused spare capacity compared to a equal one with a lower amperage..

Which is better a 600mA or a 500mA?

So basically, a 600mA will be at least as good as a 500mA, since the new Volts require less current. Aelus is 100% right. To put it another way, the voltage supplied has to be correct for the device. However, the actual current draw will be determined by the device itself, not the power supply.

## What’s the difference between 500mA and 1A power supply?

If a camera draws 300ma on a 500ma supply, it will draw exactly the same 300ma from a 1a supply, or a 2a supply… A power supply that can provide more amperage will just have extra unused spare capacity compared to a equal one with a lower amperage..

## When to install a 500mA or 1A fuse?

The only exception would be in a fault condition, such as a short, or a faulty camera, in which case the more amperage the psu can supply, the more damage can occur….. Best bet would be to install a suitable fuse if your power supply amperage is much bigger than the needed amperage for the device, so in a fault, the fuse blows.