G-13 Coin Recognition Failure: Cold Weather Diagnosis -... | terminalfaults.org

Technical Background:

The G-13 coin recognition system utilizes inductive proximity sensors to detect coin dimensions and material composition. These sensors rely on stable voltage (24V DC) and consistent signal processing. Extreme cold can alter sensor calibration, increase resistance in circuit pathways, and cause signal attenuation or drift leading to recognition errors. The CPU uses a 9600 baud rate serial communication to process sensor readings.

Symptoms:

The G-13 coin recognition system fails to accurately identify or validate coins. Failures are reported at or below -30°C.

Possible Causes:

1. Temperature-induced drift in coin recognition sensor calibration.
2. Increased resistance in sensor wiring and connectors due to cold, affecting signal strength.
3. Reduced voltage output from the 24V DC power supply under load in extreme cold.
4. Condensation forming on sensor surfaces, disrupting inductive field readings.
5. Degradation of the coin validator's internal oscillator frequency due to temperature changes, skewing timing measurements.
6. Cold-related embrittlement or cracking of sensor housing or mounting, causing misalignment.

Solution:

1

Verify 24V DC power supply output under load at operating temperature. Use a calibrated multimeter.
2

Inspect sensor wiring and connectors for corrosion or damage. Clean and reseat connectors.
3

Use a calibrated IR thermometer to measure the temperature of the coin recognition sensors during operation and compare to factory specifications.
4

Examine the coin validator for signs of condensation. Ensure proper ventilation to prevent moisture buildup.
5

Upload factory default calibration settings using a direct serial connection to the mainboard (if available).
6

Check and clean the coin path to eliminate obstructions.
7

If possible, implement a heating element to maintain the coin validator above its minimum operating temperature.

Safety Warning:

High voltage (24V DC) is present within the G-13 coin validator. Power down and disconnect the device from the main power supply before performing any maintenance or inspection. Use appropriate personal protective equipment (PPE), including insulated gloves. Follow safe handling practices. Do NOT use water or conductive cleaning solutions.

Prevention:

Regularly inspect the coin validator for debris and corrosion. Ensure proper ventilation to minimize condensation. Monitor the ambient temperature and consider installing a heating element if temperatures frequently fall below the device's operating range. Clean coin recognition sensors with a dry, lint-free cloth on a quarterly basis.

Expert Tip:

Check the coin validator's internal clock. Inaccurate timekeeping can sometimes affect the algorithm for coin recognition. Resetting to the correct time, or syncing to an NTP server, might improve accuracy. Furthermore, shield the 24V power wires with ferrite beads to remove noise.

Frequently Asked Questions

•What is the operating temperature range of the G-13 coin recognition sensor?

The operating temperature range can vary. Consult the manufacturer's datasheet. A typical range is -20°C to +50°C.

•How can I prevent condensation from forming inside the coin validator?

Ensure adequate ventilation and consider using a desiccant pack to absorb moisture.

•What type of lubricant is safe to use on the coin path mechanism?

Use a dry PTFE lubricant sparingly to prevent dust buildup. Avoid oil-based lubricants.

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•What is the operating temperature range of the G-13 coin recognition sensor?

•How can I prevent condensation from forming inside the coin validator?

•What type of lubricant is safe to use on the coin path mechanism?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: