GESPAC Water Alarm Board

Specifications:

         12 VDC Power @ 100mA

         Accepts any 2 wire water sensor with probe to probe spacing of .

         Board Size 3 x 6

Description:

The DTEC Ltd. GESPAC water alarm board provides 8 water alarm inputs along with provision for a synchronous to sin converter module for use with a gyro compass and inverter. The water alarm board provides indication and protection for 8 water alarm inputs. It also provides indication of input power +12 VDC and the DC-DC converters isolated +12 VDC output. The 8 water alarm channels use an isolated supply with a relay output providing the input signal to the GESPAC digital input card. The switched relay output voltage can be selected to output either +5 VDC or +12 VDC as the system requires. The board requires +12 VDC, -12 VDC (only for synchronous/sin converter), and ground.

Stock Item. US$300.00 

Circuit Description:

The circuit description for the 8 water alarms is the same for each channel. When the 2 inputs are shorted together this causes the NPN transistor to turn on. After this transistor turns on the led should illuminate and the relay should be energized for that appropriate channel. When the relay closes the output channel goes low and is outputted. This is active low output and when the channel is not active it can be tied high to either +5 or +12 VDC by jumper JP1. A 7805 (+5 VDC regulator) is provided to supply the +5 VDC level if this is the non active level of the digital input card. The isolated supply (+12 VDC) is provided by the Lambda DC-DC converter . This is to isolate the positive and ground rail on the input side of the circuitry. An LED will illuminate for each water alarm being activated, the +12 VDC input power and the isolated +12 VDC power.

The optional circuitry provided for the synchronous to sin/cosine conversion for use with a gyro is as follows. The 3 gyro compass outputs S1, S2 and S3 are inputs to the board along with the reference voltage which is typically 24 VAC @ 400 Hz from the gyro inverter. Outputs from the synchronous to sin/cosine converter are the corrected sin and cosine values. No circuitry is provided on the board for adjusting the bias or gain of the values. The converter circuitry requires +12 VDC, -12 VDC and ground to function.

For download of Schematic and General Arrangement in DXF format go to Downloads.

Connector Pinouts

Connector P1 Screw Type Term Block

Description

1

S1 Gyro Compass Input

2

S2 Gyro Compass Input

3

S3 Gyro Compass Input

4

Reference Voltage for the Converter

5

Water Alarm Output channel #1

6

Water Alarm Output channel #2

7

Water Alarm Output channel #3

8

Water Alarm Output channel #4

9

Water Alarm Output channel #5

10

Water Alarm Output channel #6

11

Water Alarm Output channel #7

12

Water Alarm Output channel #8

13

Water Alarm Channel #8 Input A

14

Water Alarm Channel #8 Input B

15

Water Alarm Channel #7 Input A

16

Water Alarm Channel #7 Input B

17

Water Alarm Channel #6 Input A

18

Water Alarm Channel #6 Input B

19

Water Alarm Channel #5 Input B

20

Water Alarm Channel #5 Input A

21

Water Alarm Channel #4 Input B

22

Water Alarm Channel #4 Input A

23

Water Alarm Channel #3 Input B

24

Water Alarm Channel #3 Input A

25

Water Alarm Channel #2 Input B

26

Water Alarm Channel #2 Input A

27

Water Alarm Channel #1 Input B

28

Water Alarm Channel #1 Input A

29

Isolated Ground

30

-12 VDC Input Power

31

Sin Output

32

Cosine Output

33

Ground - Power Supply Common

34

+12 VDC Input Power