Micro-Cap v7.1.6 / RM

PUT

This circuit is a macro model for a PUT, a Programmable Unijunction Transistor. The macro equivalent circuit is as follows:

Figure 21-16 PUT macro equivalent circuit

The parameter definitions are as follows:

See the circuit THY1 for an example of the use of this macro.

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RELAY1

This relay model includes a user-specified coil resistance and inductance. The coil current is sensed and converted to a voltage by H1 which drives a Schmitt macro to provide hysteresis between the ION and IHOLD currents. The output of the Schmitt drives a standard voltage controlled switch S1.

Figure 21-17 RELAY1 macro equivalent circuit

The parameter definitions are as follows:

See the circuit RELAY for an example of the use of this macro.

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RELAY2

This relay model includes a flux circuit and derives a magnetizing force from the flux. It then algebraically sums the magnetizing, stop, friction and restoring spring forces acting on the relay plunger to arrive at a net force which is integrated once to get the plunger velocity and again to get the plunger position. This plunger position directly controls the switch contacts.

Figure 21-18 RELAY2 macro equivalent circuit

The parameter definitions are as follows:

See the circuit RELAY for an example of the use of this macro.

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RESONANT

This macro implements a resonant circuit with a resistor, capacitor, and inductor. The L value is entered as an input parameter, LIN. The C value is computed from the LIN and F0 input parameters. The resistor is computed from all three input parameters. The implementation is as follows:

Figure 21-19 RESONANT macro equivalent circuit

The parameter definitions are as follows:

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SCHMITT

This circuit is a macro model for a Schmitt trigger, a circuit with a large number of uses, including noise filtering, hysteresis, and level shifting. The circuit looks likethis:

Figure 21-20 SCHMITT macro equivalent circuit

The parameter definitions are as follows:

See the circuit OSC1 for an example of the use of this macro.

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SCR

This circuit is a macro model for a silicon controlled rectifier or SCR. The macro equivalent circuit is as follows:

Figure 21-21 SCR macro equivalent circuit

The parameter definitions are as follows:

See the circuit THY1 for an example of the use of this macro.

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SLIP

The SLIP macro models hysteresis, or backlash. The output is zero within the slip zone, -DX to +DX. Outside of the hysteresis zone, the output is proportional to the input. The output is clipped to MAX.

This function is implemented with the SLIP macro:

Figure 21-22 SLIP macro equivalent circuit

A pair of input parameters, DX and MAX, define the slip zone and the maximum output level. The function is constructed with an NTVOFV Function table source.

See the circuit SYSTEM2 for an example of the use of this macro.

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SPARKGAP

This is a macro circuit model for a spark gap arrestor.

Figure 21-23 SPARKGAP macro equivalent circuit

See the circuit SPARK for an example of the use of this macro.

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SUB

A common requirement is to subtract two analog signals. The desired function is:

VOut(t) = ka Va(t) - kb Vb(t)

This function is implemented with the SUB macro:

Figure 21-24 SUB macro equivalent circuit

The two input parameters, KA and KB, scale each input. The scaled input signals are then subtracted to produce the output. This implementation is done with an NFV function source.

See the circuit SYSTEM2 for an example of the use of this macro.

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SUM

Many systems simulations call for a function to perform the analog addition of two signals. The desired function is:

VOut(t) = ka Va(t) + kb Vb(t)

This function is implemented with the SUM macro:

Figure 21-25 SUM macro equivalent circuit

The two input parameters, KA and KB, scale each input. The scaled input signals are then added to produce the output.

See the circuit SYSTEM2 for an example of the use of this macro.

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