DGH Corporation Supplementary Help-Desk: DGH Module Trigger Clock

DGH Module Trigger Clock
for Radio Modems

Overview
The DGH modules allow for conversions either continuously or upon a request. However, when used with radio modems the continuous output will tend to flood the radio modem system and is often not required at the rate at which the module provides the data.

With the aid of the circuit shown below the DGH module can, with the CONT pin, send a conversion at a time interval required.

Circuit Description
The 4060 is an oscillator/divider device. Every time Q14 drops (a complete count of 16384 oscillations) the first flip-flop of a 4013 device triggers. This in turn triggers the second flip-flop which brings the CONT pin of the DGH module low, forcing it to complete a conversion and send it's data.

The LED is used to indicate a trigger has happened and remains on until Q4 goes high. Should the LED remain on for too short a time pin 4 of the 4013 can be alternatively connected to any of the remaining outputs (Q5..Q13) of the 4060.

The second flip-flop will remain on until there is transmission from the DGH module. The module requires that the CONT pin is held low until there is transmission. If an indication is required that the DGH is transmitting, a LED in series with a 3k3 resistor could be wired between pin 13 of the 4013 and GND.

Timing
The oscillator resistor values have been calculated to give approximately a pulse per second per 1nF of capacitance of Cn. For example a 'once per minute' pulse would require approx 60nF on Cn, this could be created by using a 56nF and a 3.9nF capacitor in parallel.

If there are any questions please email

NOTE: This webpage does not form part of any official documentation.
Any information contained herein is used at own risk.