The first integrated version of O-ESD, designated as v0.5, has four physical parts
1) Grip that provides
- power supply from two 18650 3.7V batteries,
- battery charging (optional),
- mechanical grip of the whole O-ESD and
- fire (push) button.
Inputs:
* USB for battery charging through chargers (optional)
Outputs:
* S1 & S2 (fire button open/short), battery outputs (B1+ & B2+) and ground (GND).
2) Micro-controller unit (MCU) that consists of
- micro-controller,
- DC/DC converters from power supply to needed voltage levels,
- LCD for user interface,
- two push buttons and one rotary encoder for the user interface,
- transformer with control (transistor) and
- filter for feedback from shaper to micro-controller.
Inputs:
* S1, S2, B1+, B2+, GND (from Grip)
* feedback (from shaper)
Outputs:
* trafo time-varying high voltage (to cascade) and
* 5V DC for high-voltage reed relay (to shaper)
3) Cascade that consists of
- high voltage cascade.
Input:
* trafo time-varying high voltage (from MCU)
Output:
* final DC high voltage (to the shaper).
and
4) Shaper that consists of
- electrical circuit with printed capacitors and inductor for ESD pulse shaping,
- high-voltage reed relay (switch) and
- control for high-voltage relay.
Inputs:
* 5V DC for reed relay (from MCU),
* reed relay control (from MCU) and
* final DC high voltage (from the shaper).
Outputs:
* ESD pulse (to the device under test) and
* feedback (to MCU).
The parts are kept together on a laser-cut acrylic glass for mechanical support.
Splitting into parts is done to make testing and improvements easier. Namely, changing one part is independent of other parts, as long as the inputs and the output are the same.
The complete bill of materials can be found in “Bill_of_materials.txt” file.
The schematics, production files and photos of assembled parts can be found in the folder 1-Hardware.
Software for the micro-controller can be found in the folder 2-Software.
Measurement results obtained using a standardized ESD target mounted on the large square aluminum plate can be found in the folder 3-Measurements, using the best available equipment at the School of Electrical Engineering and local accredited EMC laboratory (Idvorsky laboratories). Results obtained from measurements confirm that all standardized levels for the current of the ESD pulse are within the allowed tolerances (designated with black lines on the plots).
The photo of one of the assembled prototypes is shown in the file O-ESD_v0.5_assembled.jpg.
Note that this is the first integrated version of O-ESD. It has all the core technical functionalities, but it is still being tested and improved.
