Why are my 2-way switch bulbs flickering?

Depending on how a 2-Way Switch has been wired by the electrician, sometimes it can cause LED and CFL bulbs to briefly flicker every now and then while the switch is off. It may be anywhere from 10 to 30 seconds between flickers, and the flicker may not be very bright, but it is not ideal nonetheless. Our engineers have tested and reproduced this scenario and have come up with the cause and a very simple solution to the problem. Click here for a full explanation and solution to this issue.


Can I get dimmable LED bulbs?

Dimmable LED bulbs are not that common, and there are several reasons for this, including the higher cost associated with dimmable capable LED drivers, and the larger physical size making them difficult to fit into smaller bulbs such as MR16 bulbs.

However, one of the main reasons is because with current dimming technology it can be quite difficult to match dimmable LED bulbs with commonly available dimmers (such as mains leading and trailing edge dimmers available from electrical wholesalers) that are typically found in homes. Many of these dimmers require a certain amount of electrical current to operate, and therefore require a minimum loading.

LED bulbs draw very little power, and because they have internal switch mode drivers they actually draw less power if they are dimmed. This means that many LED bulbs when driven from commonly available dimmers (such as Clipsal, PDL etc) will flicker at low brightness, or will fail to turn on.

The engineers at LEDstuff are working hard to bring suitable dimmable products to our customers. We stock the Kiwi Electronics K004U Universal Dimmer as we have found it is more reliable with LED products than other available dimmers, and we fully test dimmable LED products before advertising their dimming functionality. If you are looking for dimmable LED products, please feel free to contact us to discuss your requirements.


I have replaced my halogen MR16 bulbs with LEDs and they are not operating properly. What can I do?

A large percentage of households in New Zealand have had 50W halogen MR16/GU10 bulbs installed over the last 20 years, either in the form of a spot light or a down light, mainly because they were considered more efficient than traditional incandescent bulbs. In fact, the 50W halogen downlight was the bulb with the highest hours of use in New Zealand in 2006[1]. Additionally, low voltage MR16 halogens were preferred due to their increased efficiency and longer service life. This is despite MR16 halogen bulbs requiring an AC transformer to run the halogen from 12V alternating current.

However, the benefits were minimal, and with the advent of modern LED lighting technology, there is a large demand to now replace these halogen MR16 bulbs with LED equivalents offering a 10‑fold increase in both efficiency and lifespan.

In general, LED bulbs can directly replace an MR16 bulb with no fuss. However, in about 1‑in‑10 cases the halogen transformer is not compatible. This can result in one of the following situations:

  1. The AC transformer output is poorly regulated, resulting in the LED bulb flickering slightly. This can occur sometimes when the driver internal to the LED bulb is not capable of filtering the AC supply from the transformer. In this case, another LED bulb may operate better, however it is best to replace the transformer with a DC output power supply. We have a full range of power supplies, view them here.
  2. The AC transformer has been designed to cut‑off below a minimum load power. When an LED bulb is inserted, drawing much less power than the transformer is rated for, it will simply shut off the output. This typically occurs when a single bulb is powered from a transformer as opposed to 2 or 3 bulbs run from a single transformer. The solution here is to replace the transformer with a DC output power supply.

If you have any questions, please talk to or email our team about your situation and we can recommend a product that suits your application.

Note: If your halogen MR16 bulbs are dimmable from a leading edge or trailing edge dimmer, it is unlikely the LED bulbs can also be dimmed. This is because low voltage MR16 LED bulbs are not typically designed to be dimmed, and even when they are, there are often issues of compatibility with the transformer.

[1] LIGHTING IN NEW ZEALAND HOMES – lighting efficiency as a sustainability indicator, 2009, https://www.branz.co.nz/cms_show_download.php?id=04e6aad5be81dcf9fe6d844d2bca85ad46cbe3f9


What does the SELV rating on my power supply mean?

Safety (or separated) Extra Low Voltage is a type of circuit used to construct some constant voltage power supplies and constant current drivers, including our MEAN WELL ranges. Power supplies that meet this standard carry the “SELV” label and have a low risk of dangerous electrical shock. They must have the following two features:

  • Electrical protective separation (i.e. double insulation, reinforced insulation or protective screening) from all other circuits other than SELV and PELV (Protected Extra Low Voltage) i.e. all circuits that might carry higher voltages.
  • Simple separation from other SELV systems, from PELV systems, and from Earth (ground)


The safety of a SELV circuit is provided by:

  • The extra-low voltage
  • The low risk of accidental contact with a higher voltage
  • The lack of a return path through earth (ground) that electric current could take in case of contact with a human body


The design of a SELV circuit typically involves an isolating transformer, guaranteed minimum distances between conductors and electrical insulation barriers.