We require a design for a PWM circuit board design and test to do the following:
- Operate up to 30V, with over voltage protection on input.
- LED for input power, output enabled, current limit
- Operate up to [url removed, login to view] max current with a 40 degree C ambient, no airflow available, will be in plastic enclosure
- Ability to set the output voltage from 0 – 100% of available supply voltage (8 bit accuracy)
- Suitable output filtering to limit noise
- Soft start (0.1 to 5 seconds in 0.1 steps from off to preset level)
- I2C interface to control all settings
- Control should be using a PIC microcontroller
- Data connections should be Via Molex or similar, 2 connectors for I2C one in one out, Power connections should be suitable screw terminals for 0.5 to 2.5 sq mm cable, the board should have 4 + ve output connections and 4 Ground output connections. ICD interface for programming should also be via suitable connector.
- Selectable I2C Address (DIP switch, up to 256 addresses)
- I2C should run at 100Khz clock
- Settable current limit from [url removed, login to view] to [url removed, login to view], upon current limit being exceeded for greater than 0.5 seconds then the unit should disable the output, checking every 3 minutes or an I2C reset command is received.
- Ability to read back current input voltage and output voltage (8-12 bit accuracy acceptable)
- Reverse polarity protection etc should be provided
- Ideally all components should be readily available in the UK via RS ([url removed, login to view]) or Farnell ([url removed, login to view])
- PIC C code
- Command and function list and description
- Schematics and PCB layout
- 1 off sample board built and tested
Please provide indication of estimated size of board (L, W ,H), we will the agree a size at award of contract. Successful completion and quality of work will likely result in future projects.
All IP and designs will be retained by the awarding company an NDA must be signed at contract award.
Quick responses would be appreciated.