0 to 15 VDC detect circuit for microcontroller
Budget: $30 – $250 USD
I am looking for a skilled electrical designer to design a 0 (OFF) to 12 VDC nominal (ON) detect circuit for my microcontroller project.
The purpose of the circuit is to determine when the circuit it is connected to is energized (+10 to 15 VDC) or not (~0 VDC). The connection to the circuit monitored must be high impedance so as to not influence it (with resistance or current consumption). The ideal output from this circuit to a microcontroller would be < 0.99 V when the monitored circuit is not energized, and between 2.31 and 3.3 V (3.0 V nominal ideal) when the monitored circuit is energized. The output will be read by a 3.3V microcontroller as a digital input (< 0.99 V = LOW, > 2.31V = HIGH). The output cannot present a current draw greater than 5 mA to the microcontroller digital input. A supply voltage of 3.3 VDC and a ground is available from the microcontroller for any of the components.
All components in the circuit must be through-hole (no SMD) and able to be sourced from mouser.com, and they must be "In stock" and "normally stocked" at mouser.com. I already have the following operational amplifiers, so if they could be used and meet the functional requirements, that would be beneficial: Mouser Part Numbers: 595-LM358P, 595-LM311P, 595-TL072CP, 595-TL082ACP, 926-LMC6482AIN/NOPB.
The final deliverables will be:
- A complete electrical schematic showing the connection to the monitored circuit (V+, V-), the connection to the microcontroller digital input, connection to the microcontroller ground (GND), and any +3.3V supply requirements from the microcontroller.
- A list of the components in the electrical schematic, including the full Mouser Part Number (P/N).
- It is not necessary to list the Mouser part number for any standard electrical components such as resistors or capacitors, but the values (ohms, tolerance, uF, type, etc) for them must be identified.
- A description of how the circuit works, including how the requirements for each component were selected, and the calculations performed to identify the component requirements.
The ideal candidate will have experience designing circuits for input signals in this voltage range. I only require the design of the circuit in the form of an electrical schematic, and not the building of it. The microcontroller I will be a 3.3V logic microcontroller.
Ideal Skills and Experience:
- Experience designing electrical circuits.
- Experience with circuits for microcontroller digital I/O.
- Ability to understand and work with specific microcontroller types
The purpose of the circuit is to determine when the circuit it is connected to is energized (+10 to 15 VDC) or not (~0 VDC). The connection to the circuit monitored must be high impedance so as to not influence it (with resistance or current consumption). The ideal output from this circuit to a microcontroller would be < 0.99 V when the monitored circuit is not energized, and between 2.31 and 3.3 V (3.0 V nominal ideal) when the monitored circuit is energized. The output will be read by a 3.3V microcontroller as a digital input (< 0.99 V = LOW, > 2.31V = HIGH). The output cannot present a current draw greater than 5 mA to the microcontroller digital input. A supply voltage of 3.3 VDC and a ground is available from the microcontroller for any of the components.
All components in the circuit must be through-hole (no SMD) and able to be sourced from mouser.com, and they must be "In stock" and "normally stocked" at mouser.com. I already have the following operational amplifiers, so if they could be used and meet the functional requirements, that would be beneficial: Mouser Part Numbers: 595-LM358P, 595-LM311P, 595-TL072CP, 595-TL082ACP, 926-LMC6482AIN/NOPB.
The final deliverables will be:
- A complete electrical schematic showing the connection to the monitored circuit (V+, V-), the connection to the microcontroller digital input, connection to the microcontroller ground (GND), and any +3.3V supply requirements from the microcontroller.
- A list of the components in the electrical schematic, including the full Mouser Part Number (P/N).
- It is not necessary to list the Mouser part number for any standard electrical components such as resistors or capacitors, but the values (ohms, tolerance, uF, type, etc) for them must be identified.
- A description of how the circuit works, including how the requirements for each component were selected, and the calculations performed to identify the component requirements.
The ideal candidate will have experience designing circuits for input signals in this voltage range. I only require the design of the circuit in the form of an electrical schematic, and not the building of it. The microcontroller I will be a 3.3V logic microcontroller.
Ideal Skills and Experience:
- Experience designing electrical circuits.
- Experience with circuits for microcontroller digital I/O.
- Ability to understand and work with specific microcontroller types