ECE Board Exam case studies
ECE Board Exam · Put your knowledge to work in context.
The Electronics Engineer (ECE) licensure examination is the Philippine government's licensure examination for entry into the electronics engineering profession. It is administered by the Professional Regulation Commission (PRC), the agency mandated to implement the regulatory laws and policies for the regulated professions, through the Professional Regulatory Board for Electronics Engineering. The ECE Board Exam case studies are 5 cases and about 3,746 words.
1Log-Linear Fit of a Capacitor Discharge: Is the Fourth Point Real?
A technician discharges a 20 µF capacitor from 10.00 V through a 150 kΩ resistor and logs the voltage with a 4½-digit DMM once per second: at t = 0, 1, 2, 3, 4, 5 s the readings are 10.00, 7.17, 5.13, 3.68, 3.10 and 1.89 V. A repeat run reproduces every reading within 0.01 V except the t = 4 s value, which repeats at 3.09–3.11 V.
634 words, about 3 min2Bias Divider Versus Emitter Degeneration in a Wide-hFE Production Run
A common-emitter stage is to be built with NPN devices from three suppliers quoting hFE(min) = 50, 100 and 200 at IC ≈ 2 mA. The design has VCC = 12 V, RC = 2.2 kΩ, RE = 470 Ω, a base divider of 47 kΩ to VCC and 10 kΩ to ground, and VBE is taken as 0.70 V.
774 words, about 4 min3A Sealed Enclosure That Cannot Get Rid of 20 W
An enclosed 400 W power supply contains a switching MOSFET dissipating 11 W; the rest of the unit adds 9 W. The MOSFET is a TO-220 (RθJC = 1.4 °C/W) bolted through a 0.25 mm pad (RθCS = 0.6 °C/W) to an extruded heatsink rated 4.5 °C/W, a figure the vendor measured in still air at a 75 K rise.
738 words, about 4 min4Adding a Second Controller to a 4–20 mA Loop
A 24 Vdc supply (adjustable 24–28 V, ±5 % at whatever it is set to) feeds a two-wire pressure transmitter whose datasheet requires at least 12 V at its terminals at 20 mA, a 600 m run of 0.75 mm² copper (≈47 Ω/km for the loop), and a 250 Ω input resistor at the PLC. A panel indicator that must be inserted in series drops 2.0 V.
801 words, about 4 min512-bit or 16-bit ADC for a 0.2 mV Requirement?
An eight-channel 12-bit SAR ADC with VREF = 5.000 V, a 20 pF internal sample capacitor and a multiplexer on-resistance of 200 Ω scans eight sensor channels at 20 kS/s each. Each channel arrives through a 10 kΩ series resistor from a remote sensor; nothing is buffered, and the only capacitor on the board is 100 nF placed at the sensor end of that lead, not at the ADC pin.
799 words, about 4 min