Designing and prototyping a switching board

Hello, and thanks for considering working with us.

We organized the information into two parts: the first one, called “The Board”, is related to the required work. The second one is called “Expected answer” and explains what specific information we need to know about you.

We are looking for someone who can design and prototype 3 circuits. It is not a complex work. However, we explained it in great detail to avoid wasting your time and ours. Please read it and do not hesitate to ask for further information.

Let’s begin.

The board

The circuits are:

- CIRCUIT 1: Power Path Management

- CIRCUIT 2: Control circuit.

- CIRCUIT 3: Sensibility regulator.

The first 2 circuits are controlled from an ESP8266 ESP12 that sends a signal in 3,3 V. The last one feeds the ESP8266 ESP12 as an input and should also have a logical level of 3.3 V. They are almost independent from each other but should be in the same board.

CIRCUIT 1: Power Path Management

It is a switching circuit (b) that commutes between a LI-Ion battery (d) and a wall adapter (a) and it could be fed from both of them. The wall adapter is always preferred before the batteries if both are available. The output from the SWITCH (b) is always the same and does NOT depend on the path. When the wall adapter is not available, the output should be from the battery.

The input from the battery (h) has a range in between 3,7 V at the lowest and 4.2 V as higher. So, it gets necessary to place a SET-UP circuit (e) to level the output up with the one from the wall adapter. Note that, this circuit (as well as the Li-Ion charger) SHOULD NOT be designed neither prototyped. As the SET-UP circuit, we will use a commercial board, so we only need pads for allowing soldering or some sort of connector. The Li-Ion charger and Set-Up ARE NOT into the development requirements. They are in the drawing only for clarity purposes.

As you see in the picture, when the wall adapter (red input) is available (on, plugged in) there must be an output which is going to be connected to a Li-Ion battery charger (f).

While switching, in the point (g), when wall adapter becomes unavailable, the output voltage should never drop below 3 V.

 

CIRCUIT 2: Control circuit.

It corresponds to 4 switches’ circuits: SWITCH 1 to 4 in the picture.

The first 3 ones (SWITCH 1 to 3) will turn “on” and “off” an equal number of LEDs. They will receive a PIC SIGNAL level of 3,3 V (c) and will be connected to 3 LEDs (e).

The last one (SWITCH 4) is a switch that turns “on” and “off” a motor. It will receive 5V (instead of 3,3V) and will be connected to a motor (f).

Again, we are only looking for the design and prototype of the switch circuits (SWITCH 1 to 4) so we only need pads for allowing soldering or some sort of connector. Other elements have been drawing only for clarity purposes.

CIRCUIT 3: Sensibility regulator.

This circuit will send a signal “on” or “off” while sensing an INFRARED SENSOR. The idea is to get sensibility adjustments from the hardware instead of software, just a basic circuit with an OpAmp and a preset. The sensor will be a cny70, tcrt5000 or similar.

Here, only the SENSIBILITY REGULATOR should be designed and prototyped, so we only need pads for allowing soldering or some sort of connector. Other elements have been drawing only for clarity purposes.

EXPECTED ANSWER

Please let us know these 3 important points:

- The price for the design and the 3 prototypes. Consider that, the prototypes should be sent to Buenos Aires (Argentina).

- The time you will required to finish the work.

- Whether you are able/willing to mass manufactured (from 10 to 100 PCS). In case you answer is yes, please give us an approximate cost per unit (of the total board).

Please, see the attached file. There you can see the description with a more understandable format and pictures.

Diseño de circuitos Ingeniería eléctrica Electrónica Ingeniería Diseño PCB

Nº del proyecto: #17467206

Sobre el proyecto