Wireless weighing

 

Wireless systems typically are battery driven systems. It is essential to have a low current consumption of all the components. The new ZigBee standard introduces an attractive solution for the RF communication. But what about the sensor? Metal strain gages themselves draw 3 mA and more when connected to a 3 V supply. This easily exceeds the acceptable current consumption.

 

The PSØ2 with its innovative PICOSTRAIN measuring principle reduces the current into the strain gage plus converter down to the µA range. Thanks to PSØ2 also metal strain gages can now be used in wireless applications at a reasonable battery size.

 

Current estimation for a slave made of 1 kOhm strain gage + PSØ2 + ATmege (µC) + Chipcon (ZigBee) transceiver:

Interrupt Rate:	0,5 Hz	1 Hz	1,5 Hz	2 Hz	5 Hz
Mittlerer Strom:	100 µA	200 µA	290 µA	380 µA	920 µA
Batterielebensdauer in h bei einer 180 mAh Batterie: 2200 mAh Batterie:	1700 21000	920 11000	630 7700	480 5800	200 2400