DC192A

Demo Circuit (DC) 192A Quick Start Guide Description The DC192 is a collection of subcircuits to support the LT1684 in ring signal generation. This board contains the hardware to facilitate demonstration of the LT1684 in several different system modes of operation. For ease of use the DC192A is designed to operate from a single 5V input supply. It utilizes the popular Microchip PIC16C73 microcontroller for the generation of the ring signals, cadence, zero crossing output, connect output, and various other specialized features detailed further in the Step by Setup 1 Generic mode Perhaps the most generic setup for the DC192A is the 20Hz 3 REN Cadenced ring. This is the setup the Demo Circuit is shipped with. In the generic mode the board is configured to demonstrate its ability to ring a phone. 1. Insure that the jumpers configure the board as setup 1. 2. Connect +5V and Gnd to the board via J2 (center+) or TP3 +5V and TP5 Gnd. 3. Plug phone into J1 or attach Tip to TP2 and Ring to TP1. Or 4. Attach oscilloscope ground lead to TP1 and the probe to TP2. 5. Power up the board observe that LED1 and LED4 are illuminated. 6. Depress SW1 and observe the results: A. A cadenced ring signal appears at the output to be seen and/or heard. B. LED2 illuminates to indicate the connect condition while TP13 (RELAY) is pulled to ground. (Remember this board is isolated so the scope ground on TP1 is not connected to the input ground on TP5, the RELAY signal is pulled to the TP5 ground.) C. A short pulse appears on TP14 (ZERO) a few milliseconds prior to each zero crossing. D. LED4 twinkles as the duty factor of its drive is modulated with the 20Hz ring signal. The effect of holding SW1 down continuously can be obtained by emplacing jumper 14 to short its terminals, or by shorting TP4 (CADENCE) to ground (TP5). Other Setups At present other setups are best described in the jumpers file (appended to the end of this document). As other modes of operation are incorporated this document, and the firmware will be updated to implement, and document the new modes. JUMPER CONFIG OCT 7 99 JP10 IS CW/CADENCED SELECT IN = CW OUT = CADENCED WHEN IN: IF 1) JP14 IS IN OR 2) SW1 IS DEPRESSED OR 3) CADENCE IN IS PULLED LOW THEN CONTINOUS SINEWAVE IS OUTPUT. ELSE CONTINOUS ZERO IS OUTPUT WHEN OUT: IF 1) JP14 IS IN OR 2) SW1 IS DEPRESSED OR 3) CADENCE IN IS PULLED LOW THEN CADENCED SINEWAVE IS OUTPUT ELSE CONTINOUS ZERO IS OUTPUT Last printed 1/31/03 2:19 PM Page 1 of 4 Demo Circuit (DC) 192A Quick Start Guide JP12 IS CONNECT RELAY MODE IN = TEST OUT = NORMAL WHEN JP12 IS IN AND JP10 IS IN AND IF 1) JP14 IS IN OR 2) SW1 IS DEPRESSED OR 3) CADENCE IN IS PULLED LOW THEN CONTINOUS SINEWAVE IS OUTPUT. THE CONNECT RELAY (TP13) IS ENERGIZED EVERY EIGHTH CYCLE ELSE CONTINOUS ZERO IS OUTPUT THE CONNECT RELAY (TP13) IS DE-ENERGIZED CONTINOUSLY WHEN JP12 IS IN AND JP10 IS OUT AND IF 1) JP14 IS IN OR 2) SW1 IS DEPRESSED OR 3) CADENCE IN IS PULLED LOW THEN CADENCED SINEWAVE IS OUTPUT. THE CONNECT RELAY (TP13) IS ENERGIZED EVERY EIGHTH CADENCE ELSE CONTINOUS ZERO IS OUTPUT THE CONNECT RELAY (TP13) IS DE-ENERGIZED CONTINOUSLY WHEN JP12 IS OUT AND JP10 IS IN AND IF 1) JP14 IS IN OR 2) SW1 IS DEPRESSED OR 3) CADENCE IN IS PULLED LOW THEN CONTINOUS SINEWAVE IS OUTPUT. THE CONNECT RELAY (TP13) IS ENERGIZED CONTINOUSLY ELSE CONTINOUS ZERO IS OUTPUT THE CONNECT RELAY (TP13) IS DE-ENERGIZED CONTINOUSLY WHEN JP12 IS OUT AND JP10 IS OUT AND IF 1) JP14 IS IN OR 2) SW1 IS DEPRESSED OR 3) CADENCE IN IS PULLED LOW THEN CADENCED SINEWAVE IS OUTPUT. THE CONNECT RELAY (TP13) IS ENERGIZED EVERY CADENCED CYCLE ELSE CONTINOUS ZERO IS OUTPUT THE CONNECT RELAY (TP13) IS DE-ENERGIZED CONTINOUSLY Last printed 1/31/03 2:19 PM Page 2 of 4