Tech Notes

Applies to Models: 7224, 7234, 7548, 7795, 7796 and 7796HC

This document assumes competence on the part of the reader in terms of amplifier systems, electronic components, and good electronic safety and working practices.

SIM Interlock I/O 25-pin Connector

AE Techron 7000-series amplifiers come with a SIM-BNC input module that also contains a female, 25-pin D-Sub connector. This connector can be used to provide remote control and monitoring of the amplifier. The connector can also be used for some multiple-amplifier applications.

The information provided here will instruct you in the wiring of several control and status applications including:

• Run status
• Overtemperature status
• Overload status
• Overvoltage status
• Reset after Overtemperature or Overload error
• Remotely Enable amplifier / place in Standby
• Current monitor

The Remote Status and Control Pinouts illustration maps the pins used for these applications. Click here for a detailed chart of all DB-25 connector pinouts (pdf format).

Remote Amplifier Status and Reset

Using the SIM-BNC Interlock connector located on the back panel of the amplifier, you can perform remote monitoring of one or more amplifier conditions including Run, Overtemperature, Overload and Overvoltage. If desired, you can also remotely reset the amplfier when forced to Standby condition due to Overtemperature or Overload conditions.

Remote Signal of Over Temperature Condition

Purpose: LED, when lit, signals Over Temperature condition.
Method: Use a 6mA series resistor of 4.02K-ohm for LED or OPTO, tie OverTemp Out (PIN 11) to -24V source (PIN 16).
Signal Type: DC
Level when Asserted: -24V
Level when Deasserted: 0V
Note: When amp is normal, this pin is pulled to –24V through a 47.5K-ohm resistor; when amp is in OverTemp state, transistor Q37 turns on and sources chassis ground as an output. Do not exceed 20 milliamps.

OverTemp condition will force amp to Standby. The amp will automatically move to Run when temperature cools to operating levels.

Remote Signal of Run Condition

Purpose: LED, when lit, signals Run state.
Method: Use a 6mA series resistor of 4.02K-ohm for LED or OPTO, tie Run (PIN 12) to -24V source (PIN 16).
Signal Type: DC
Level when Asserted: -24V
Level when Deasserted: 0V
Note: When amp is in Standby mode, this pin is pulled to -24V through a 10-ohm resistor in series with two solid-state relays; when amp is in Run mode, transistor Q34 turns on and sources chassis ground as an output, energizing Mains Relays. VOUT is typically -0.03V dc. Do not apply load to ground as this could enable Relays.

Remote Signal of OverLoad Condition

Purpose: LED, when lit, signals Overload condition.
Method: Use a 6mA series resistor of 4.02 Kohm for LED or OPTO, tie OverLoad Out (PIN 23) to -24V source (PIN 16).
Signal Type: DC
Level when Asserted: -24V
Level when Deasserted: 0V
Note: When amp is normal, this pin is pulled to -24V through a 47.5K-ohm resistor; when amp is in Overload state, transistor Q36 turns on and sources chassis ground as an output. Do not exceed 20 milliamps.

OverLoad condition will force amp to Standby (default) or to Stop (when Stop Mode on Overload option is enabled). If in Standby, amp will automatically move to Run when overload is remedied. If in Stop, Reset must be triggered via front-panel Reset button or remote Amplifier Reset.

Remote Signal of OverVoltage Condition

Purpose: LED, when lit, signals Overvoltage condition.
Method: Use a 6mA series resistor of 4.02 Kohm for LED or OPTO, tie OverVoltage Out (PIN 24) to -24V source (PIN 16).
Signal Type: DC
Level when Asserted: -24V
Level when Deasserted: 0V
Note: When amp is normal, this pin is pulled to -24V through a 47.5K-ohm resistor; when amp is in Overvoltage state, transistor Q29 turns on and sources chassis ground as an output. Do not exceed 20 milliamps.

Reset from Standby or Stop

Purpose: Switch, when thrown, returns amp to Ready/Run condition after Overtemperture or Overload conditions.
Method: Use a dry-contact switch, voltage regulator (MC7915), and two 0.01/50V capacitors; wire the circuit as shown (below). Assert 15V for at least 100 ms to clear the error condition. Note: Do not hold low.
Signal Type: DC
Level when Asserted: -15V
Level when Deasserted: 0V
Note: Tie to PIN 13 (-24V dc) and create a -15V dc source; <2mA required for reset. Connect the -15V dc source to PIN 25 (Reset) through a 1K buffer resistor to reset.