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QS-KI-PWRINTF-REVB · Rev-B · KI-MPB-RevB / PCBV1.02

Quick start

PWR INTF Quick Start Guide

In seven steps

Power the board, verify the rails, then connect one load or controller function at a time.

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  • 18–30 VDC input
  • 24 V fused path
  • 12 V / 5 V / 3.3 V regulated rails
  • USB-C 5 V output only
KI Maker PWR INTF protected low-voltage DC power interface board
No AC mains · USB-C is 5 V output only · IN1/IN2 dry-contact only · A1/A2 and sensor inputs 0–3.3 V only

Read before power-up

  • Use 18–30 VDC input only. No AC mains anywhere on the board.
  • USB-C is a 5 V output only. Do not power the board from USB-C.
  • IN1 / IN2 are dry-contact / switch-to-ground inputs only. Do not apply external voltage.
  • A1 / A2 and sensor inputs are 0–3.3 V only.
  • OUT1 / OUT2 are low-side MOSFET outputs, not floating relay contacts.

5-minute first power-up

  1. Mount the boardInsulated M3 standoffs. Keep the bottom side away from conductive surfaces, loose hardware, and debris.
  2. Leave everything else offControllers, sensors, and loads stay disconnected for the first power-up.
  3. Set the fan selectorIf you will use a fan later, set 12 V or 24 V before power-up.
  4. Land the supply18–30 VDC on the main input with correct polarity. 24 V nominal is the expected use case.
  5. Watch the rail LEDsLED1 24 V input · LED2 24 V fused out · LED3 12 V · LED4 5 V · LED5 3.3 V.
  6. Measure the railsConfirm 24 V, 12 V, 5 V, and 3.3 V before connecting anything else.
  7. Add one thing at a timeOne controller signal or one load, then re-check voltage and temperature.

Expected first-use result

No unusual smell, noise, or hot spot. Rail LEDs on. Measured rails present. Then move to one basic hookup.

Most important wiring rule

OUT1 / OUT2 are low-side switches

Connect the load positive wire to the matching positive rail and the load negative wire to OUT1 or OUT2.

Do not wire OUT1 / OUT2 like floating relay contacts. Do not backfeed any rail from another power source.

Connector groups

Group Quick use
Main input18–30 VDC only. Check polarity before power-up.
24 V / OUT1 / IN124 V accessory path and low-side switched OUT1. Up to 1.0 A continuous.
12 V / OUT2 / IN212 V rail and low-side switched OUT2. Shares the 12 V rail budget.
5 V / 3.3 VController and logic/sensor supply. 5 V 1.0 A · 3.3 V 0.5 A.
USB-C5 V output only, 0.5 A max. Not a power input, not data, not USB-PD.
IN1 / IN2 SWDry-contact / switch-to-ground only. No external voltage.
A1 / A2 / Sensor0–3.3 V analog or passive NTC only.
Fan headerSelectable 12 V / 24 V fan power with PWM / TACH.

Switches — set before power-up

Switch Quick use
Fan selector12 V or 24 V fan power output.
I/O pull-upTach and SW inputs pull-up, 3.3 V or 5 V.
AnalogOn = A1+A2. Off = analog header path.

Released ratings

Continuous, open air. Do not assume every rail can run at maximum at the same time.

Rail / output Limit
Main input18–30 VDC only (24 V nominal expected)
OUT1 / 24 V pathUp to 1.0 A continuous
OUT2 / 12 V pathUp to 1.0 A continuous (shares 12 V rail budget)
5 V rail1.0 A continuous
3.3 V rail0.5 A continuous
USB-C output5 V output only, 0.5 A max

Thermal / airflow

For OUT1 / OUT2 loads above 500 mA, verify board temperature during first use. Cooling is recommended near maximum current, especially in an enclosure.

Stop immediately if…

  • You are not sure about polarity, connector identity, or whether a signal is dry-contact or voltage-based.
  • A rail reads incorrectly, an LED pattern seems wrong, or a component becomes unexpectedly hot.
  • You are about to connect 5 V, 12 V, 24 V, FAN_V, VIN, or USB-C VBUS into A1, A2, IN1, IN2, or the sensor header.

What to read next

Kuster Induction Solutions LLC · KI Maker PWR INTF Rev-B · PCBV1.02 · QS-KI-PWRINTF-REVB · Low-voltage DC only · Not for AC mains, life-safety, medical, or certified safety systems.