On Monday, 7 May 2018 11:41:41 UTC+1, J.B. Wood wrote:
On 05/06/2018 01:57 AM, tabbypurr wrote:

Glowstarters are widely available, perform poorly but work. The glowswitch is far smaller than the plastic container.
A relay with brief time delay makes a much better starter.


Hello, and I have to take issue with your "perform poorly" remark. Glow
switches (aka "starters") have been around for decades and are very
reliable. And if they're reliable and work, how do they poorly perform?

they greatly reduce the life expectanc of tubes and are unpleasant on the eye during starting.

In a traditional fluorescent lamp (hot cathode type) fixture with a coil
ballast the lamp may pulse a few times before the gas discharge path is
established. The ballast performs the functions of both a current
limiter and providing a temporary voltage boost to establish the gas
discharge path. When the glow switch disconnects after the lamp
filaments have been heated there may not be enough of a voltage boost to
fire up the lamp because of when this occurs on the AC cycle. Usually
no more than a couple of start repeats are required and that's why the
lamp pulses. In any event glow switches are quite reliable and cheap to
replace when required. Sincerely,

Not so. For a project I tested the strike rate using switch contacts instead of a glow starter. It was 100%. The reason glowstarters extinguish the lamp is purely because they're horrible glowstarters - excluding the few cases where the lamp extinguishes itself due to it failing.


NT