hps

Went to fix a 70W HPS fixture (ignitor internal to lamp) at a neighbors the other day after he mentioned it had stopped working. Said it had recently gone out and put a new new-old stock lamp in himself, but that did not last long until it went out again, so I went over and swapped the bulb over...

For those who know the Gatwick area and the short tunnel on the A23 that's between the south terminal car park and the main area of Gatwick airport, it seems to me the amount of HPS lights in the tunnel is overkill! Not to mention that a lot of the lights in the tunnel don't even work! Here...

My granddad wants a 70W HPS lamp fitted under a big tree in his garden and so I have gone ahead and order the required parts. The key parts being a TimeGuard NTT01 24hr immersion timer, a Photocell, and of course the 70W HPS light fixture. Wired like so: Fused Spur > Timer > Photocell > HPS...

So today I did a little experiment and thought I would see what would happen if one powered up a 70W HPS bulb with an internal ignitor directly on the 230v mains without using a ballast. Sadly not much happened other than a brief flash for a fraction of a second before the MCB for the circuit...