Random Flying Object
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- Jan 26, 2013
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If you have seen my L3 build you will see that I have way too many switches on my AV bay. So I decided to build a circuit to make those go away. The RC folks have some solid state switches operated by a little button or two, but after watching a fellow rocketeer nearly loose a rocket due to one of these circuits I figured it best to start from scratch.
The current circuit design has two buttons and/or digital inputs to start and stop the solid state switch(es). It has two power inputs, one for an altimeter, one for pyro and the corresponding outputs. A push of the start button and everything comes to life. Press and hold the stop button and everything shuts down. Sounds fairly basic until you consider all the other crazy stuff that goes along with a rocket. If the incoming power circuit is noisy, maybe due to a bad weld joint in a 9V battery, etc. The circuit will remain in the on position and filter the power going to the altimeter so it doesn't reset in flight. Or say for instance a button starts shorting or triggering due to vibration, etc. The circuit assumes all inputs are startup commands unless the stop button is held in place for 10s while the start button is released. Maybe you have a low battery or some hogg of an igniter and when it fires it drops your voltage below the operating voltage of the altimeter. The circuit maintains filtered power to the altimeter while the pyro fires in addition it keeps the pyro and altimeter power circuits latched on.
Here is the first test of the power circuit with a TeleMega. Several boards will soon be released to beta testers. After testing I will make a production run and offer them for sale.
Sent from my iPad using Rocketry Forum
The current circuit design has two buttons and/or digital inputs to start and stop the solid state switch(es). It has two power inputs, one for an altimeter, one for pyro and the corresponding outputs. A push of the start button and everything comes to life. Press and hold the stop button and everything shuts down. Sounds fairly basic until you consider all the other crazy stuff that goes along with a rocket. If the incoming power circuit is noisy, maybe due to a bad weld joint in a 9V battery, etc. The circuit will remain in the on position and filter the power going to the altimeter so it doesn't reset in flight. Or say for instance a button starts shorting or triggering due to vibration, etc. The circuit assumes all inputs are startup commands unless the stop button is held in place for 10s while the start button is released. Maybe you have a low battery or some hogg of an igniter and when it fires it drops your voltage below the operating voltage of the altimeter. The circuit maintains filtered power to the altimeter while the pyro fires in addition it keeps the pyro and altimeter power circuits latched on.
Here is the first test of the power circuit with a TeleMega. Several boards will soon be released to beta testers. After testing I will make a production run and offer them for sale.
Sent from my iPad using Rocketry Forum