Hi,
I am building a rocket launch controller that is powered by a 9 volt battery. The control circuitry would energize a 9 volt relay and the contacts for this relay would provide the current to the rocket igniter. The problem I am having is with relay contact ratings. Not many relays give decent DC contact ratings. I know ohms law doesn't apply to contacts as DC is much harder on the contact. A typical Estes rocket igniter will draw 12-13 amps for about 150 milli seconds. Most of the designs I see on the internet for launchers are using no relay and switches rated at 2 to 2.5 amps. I question the longevity of these designs. I can't seem to find a 9vdc relay with decent ratings. Solid state relays are pricey. Does anyone have an idea?
I am building a rocket launch controller that is powered by a 9 volt battery. The control circuitry would energize a 9 volt relay and the contacts for this relay would provide the current to the rocket igniter. The problem I am having is with relay contact ratings. Not many relays give decent DC contact ratings. I know ohms law doesn't apply to contacts as DC is much harder on the contact. A typical Estes rocket igniter will draw 12-13 amps for about 150 milli seconds. Most of the designs I see on the internet for launchers are using no relay and switches rated at 2 to 2.5 amps. I question the longevity of these designs. I can't seem to find a 9vdc relay with decent ratings. Solid state relays are pricey. Does anyone have an idea?