Constant Current LED Driver OR Constant Voltage LED Driver? Series or Parallel?

So you have a job of installing some LED lights and you’re confused whether you’re meant to wire them in series or parallel.  First things first, let’s determine whether the LED lights that you’re about to install require Constant Current or Constant Voltage power supply (LED Driver, using the correct terms). Secondly, let’s see if you have the right LED driver for the job. When you buy LED lights from Astrum Lighting we take care of these things and ensure that you get the correct drivers with your light fittings.

Constant Voltage LED Drivers

  • Always in parallel
  • Observe polarity

This is the easy one – everything connects together in parallel, just like the garden lights, automotive electrical or anything that works with batteries. Prominent Constant Voltage fittings and components are: LED_striplights, 12V LED MR16 and LED G4 lamps.


This job illuminating a staircase with recessed LED strip lights required Constant Voltage LED drivers. The drivers supplied were two 12 Volt 80 Watt dimmable power supplies PSHLA-12V-80W from Task Lighting.

Constant Current LED Drivers

  • Always in series
  • Observe polarity
  • Match CC Driver to light fittings correctly.

Constant Current light fittings dictate to Constant Current driver the voltage that they require. Constant Current driver automatically adjusts the voltage to maintain the current to the LED.

Most devices around us are designed to operate at constant voltage. All those devices draw the current that they require. Our typical assumption is that voltage is constant and current is proportional to power. Let’s take an oil column heater, for example, working with round some round numbers. The oil heater is stamped 2,200W so we work out that it draws 10A. How? Because we know that the voltage is 220V. Amps vary, Volts stay constant. What is more important is that voltage fluctuations are usually bad for appliances.

Constant Current is the other way around!  Voltage varies, Current remains the Constant. This way when we connect multiple LED’s in series, voltage is divided between the number of LED lights but the current remains the same.

Drivers for LED downlights

Whether LED downlights are Constant Voltage or Constant Current, most of the time (we mean 99% of the time) they connect one-on-one, meaning one driver per downlight. The downlights come equipped with drivers, all in the same box. There should be no need to guess how they connect together.

Do you require replacement drivers for an LED light fixture? Get in touch with us to discuss your requirements or pop into our showroom in Albany, Auckland as we most certainly can help.

Leave a Reply

Your email address will not be published. Required fields are marked *