Aircraft Start Sequence Trainer/Mockup

[Pilotman Ray]

I am stuck in the middle of building a circuit for an aircraft starting mockup that will train our students to correctly start the aircraft without accidentally re-engaging the starter and thus causing very costly maintenance actions. The system is 12v.

We would like to have a 10 second delay timer switch that will turn on a light when the start sequence has been successfully completed. This part seems simple because when the ignition switch is turned to start, it closes the contacts and starts the 10 second delay timer that turns on the light if held closed for 10 seconds. I found one of these timers on amazon but could not find anything for the next part of the mock up.

The complex component of the circuit I can’t figure out is that I would like to have a buzzer in the circuit. If the student accidentally releases the ignition switch even for a moment during the 10 second starting sequence, then this buzzer would go off using something like a latch circuit that turns on and keeps a buzzer on until it is reset.

What is confounding me is how to create this circuit so that the buzzer is not going off when:
1. The system is initially powered up.
2. The contacts are closed when the ignition switch is turned on for a start sequence
3. The 10 second starting sequence is completed successfully and the starting key is released thus opening the starting circuit contacts.

We only want this buzzer to go off if the student fails to hold the ignition contacts closed during the 10 second starting sequence.

Could someone please help me design this circuit and let me know what components I need to in order to build it?

 

[berkeman]

I am stuck in the middle of building a circuit for an aircraft starting mockup that will train our students to correctly start the aircraft without accidentally re-engaging the starter and thus causing very costly maintenance actions. The system is 12v.

We would like to have a 10 second delay timer switch that will turn on a light when the start sequence has been successfully completed. This part seems simple because when the ignition switch is turned to start, it closes the contacts and starts the 10 second delay timer that turns on the light if held closed for 10 seconds. I found one of these timers on amazon but could not find anything for the next part of the mock up.

The complex component of the circuit I can’t figure out is that I would like to have a buzzer in the circuit. If the student accidentally releases the ignition switch even for a moment during the 10 second starting sequence, then this buzzer would go off using something like a latch circuit that turns on and keeps a buzzer on until it is reset.

What is confounding me is how to create this circuit so that the buzzer is not going off when:
1. The system is initially powered up.
2. The contacts are closed when the ignition switch is turned on for a start sequence
3. The 10 second starting sequence is completed successfully and the starting key is released thus opening the starting circuit contacts.

We only want this buzzer to go off if the student fails to hold the ignition contacts closed during the 10 second starting sequence.

Could someone please help me design this circuit and let me know what components I need to in order to build it?

Welcome to the PF.

This is a natural application for a small microcontroller (uC) circuit, using an Arduino for example. Do you or anybody else on this project have any experience building projects with uCs?

Alternately, you could just program this in C on a computer and use a simple USB digital IO module to give you the control signals for the LEDs and buzzer and key switch position detection circuit.

 

[dlgoff]

Could someone please help me design this circuit and let me know what components I need to in order to build it?

You may want to look into Time Delay Relays.

This image from http://www.productsforautomation.com/macromatic-tr60526-interval-time-delay-relay-p/tr-60526.htm

 

[Pilotman Ray]

Welcome to the PF.

This is a natural application for a small microcontroller (uC) circuit, using an Arduino for example. Do you or anybody else on this project have any experience building projects with uCs?

Alternately, you could just program this in C on a computer and use a simple USB digital IO module to give you the control signals for the LEDs and buzzer and key switch position detection circuit.

Unfortunately no one on this project has experience with microcontrollers or uCs. I really appreciate the suggestions and am looking up the possibility of a simple USB digital IO module. Again unfortunately no one on our team has any programing experience. We are a group of pilots and flight instructors with limited exposure in electrical engineering.

 

[berkeman]

Is there a high school or community college nearby with an Electronics Club or Robotics Club? You could propose it as a simple fun project for them.

 

[Nidum]

Have a look at latching relays .

Can be used as memory or to detect interrupts .

In industry this problem could readily be solved using a relatively low cost Programmable Logic Controller .

These devices are in such common use that you may be able to find a friendly works electrician somewhere that could set one up for you .

 

[Nidum]

The latching relay function can be implemented using standard relays and feedback circuitry . Not difficult to do and often a cheaper option than buying special purpose relays .