Requires: SmartSpice & Smartview

Minimum Versions: SMARTSPICE 4.6.5.R

The input deck simulates a resistive bridge circuit where one arm is a sensor and .DC and .MEASURE analysis are performed on the circuit. Rubberband the “.param RNOM_SENS” parameter to see effect of changing the resistor and therefore the balance of this bridge-configured circuit.

Graphics

Input Files

rubberband_example_07.in

* SENSOR BRIDGE
* Rubberband parameters:
* .PARAM RNOM_SENS - sensor output volatage

.OPTION NOMOD
VBIAS	1	0	DC	10

*
* INSTRUMENTATION BRIDGE
*
.PARAM RNOM=1K
.PARAM RNOM_SENS=1K
RB2	1	3	RNOM
RB4	3	0	RNOM
RB1	1	2	RNOM

*
* RESISTIVE SENSOR (VOLTAGE CONTROLLED)
*
XSENSOR	2 0 10 0 V_CONT_R

*
* XSENSOR CONTROL VOLTAGE
*
VCONT	10 	0	DC 1.0
RD1	10 	0	1G

*
* SUBCIRCUIT FOR VOLTAGE CONTROLLED RESISTOR
*	RESISTOR - 1,2     CONTROL - 4,5
*
.SUBCKT V_CONT_R   1  2  4  5
ERES	1       3       VALUE = { I(VSENSE) * RNOM_SENS * V(4,5) }
VSENSE	3	2	DC	0
.ENDS

*
* ANALYSIS
*
.PARAM DC_START=0.5 DC_STOP=1.5
.DC LIN VCONT DC_START DC_STOP 0.01

*
* VIEW RESULTS
*
.SAVE	DC Vsensout='v(2)-v(3)'

*
* MEASURES
*
.MEASURE dc Vsensout_min POINT   v(2,3)  ARG0 = DC_START
.MEASURE dc Vsensout_cent POINT  v(2,3)  ARG0 = "DC_START+(DC_STOP - DC_START)/2"
.MEASURE dc Vsensout_max POINT   v(2,3)  ARG0 = DC_STOP
.MEASURE dc Vsensout_width   param='Vsensout_max-Vsensout_min'

.END