Magnetic Sensor Schematic Diagram

This circuit serves as a magnetic switch. The principle of this circuit is, whenever a magnet comes close to the sensor, then the sensor will flow the output voltage to IC1. The output voltage will activate the timer which will then activate the relay controlled by IC2.

Figure 1. Magnetic Sensor

Component Part List :
Diode D1 : 1N4001
Resistor R1 : 10k ohm
Resistor R2 : 470k ohm
Resistor R3 : 1k ohm
Resistor R4 : 47k ohm
Polar capacitor C1 : 2.2 uF/16V
Polar capacitor C2 : 470 uF/16V
Transistor T1 : SL100
IC1 : NE555
IC2 : CD4013
Relay RL1 : 12 V, 200 ohm
                                                                                                           Magnetic Sensor
                                                                                                           5mm LED

Schematic diagram of prototype magnetic apogee detection sensor. Figure 1. Simplified schematic diagram. One peculiarity of the magnetoresistive sensors is

This new sensor does have a few potential drawbacks. The ejection angle does depend on E/W/N/S flight path so that it’s behavior will vary from launch to launch with a bigger variation the further south one is launching. This is due to the smaller inclination angle in these regions. It has the potential to be affected by stray magnetic fields from ferrous components in the launcher, airframe or avionics as well as the high currents in launch system. However, so far I have not seen any indications that this is a problem. This sensor only triggers the ejection and does not record any data such as one might get from an altimeter or accelerometer. Also, being sensitive to rocket orientation, it will trigger ejection if the rocket tips over on the pad.