Raaahbin wrote:While I agree about the quality of our own Aussie-grown SCR igniters, I have to say my experience with them on a standard Estes launch controller is contrary to the above: you cannot test an SCR igniter for continuity on an Estes controller. The continuity current is above the firing current threshold for an SCR igniter: I tell my kids to give the countdown, then insert the safety key, because the SCR igniter will fire at that point.
Very good point.
It is the current drawn by the incandescent globe in the Estes controllers that causes the issue.
You can simply remove the globe and the controller will work as intended, although obviously without continuity check. Neither the Safety Code or Safe Launch Practices documents require continuity check, only a safety interlock (key)
Easiest option while keeping the continuity check is to replace the standard globe with a 6V rated LED globe with a BA9S / T11 bayonet base.
The LED's draw around 20 - 40mA which is much less than the No Fire current for the SCR igniters (~150mA).