<ammeter />

Overview

<ammeter /> measures current through a circuit branch during SPICE simulation. Insert it between the two nodes of the branch you want to measure, then connect pos and neg to define the positive current direction.

An ammeter is primarily a schematic and simulation component. It emits a current probe for simulation graphs.

export default () => (
<board routingDisabled>
  <voltagesource name="V1" voltage="15V" schX={-3} />
  <ammeter
    name="AM1"
    color="#ff0000"
    connections={{
      pos: ".V1 > .pin1",
      neg: ".R1 > .pin1",
    }}
  />
  <resistor name="R1" resistance="10ohm" schX={3} />

  <trace from=".R1 > .pin2" to=".V1 > .pin2" />

  <analogsimulation
    duration="1ms"
    timePerStep="100us"
    spiceEngine="ngspice"
  />
</board>
)

Pins

Pin	Aliases	Description
pin1	pos	Positive side of the current measurement.
pin2	neg	Negative side of the current measurement.

Positive current is measured entering pos and leaving neg. Reverse the connections if the plotted current has the opposite sign from the direction you want.

Properties

Property	Description	Example
name	Label for the ammeter and its current trace.	"AM1"
connections	Connects the ammeter in series. Use either pos/neg or pin1/pin2.	{{ pos: ".V1 > .pin1", neg: ".R1 > .pin1" }}
color	Color used for the current trace in simulation graphs.	"#ff0000"
graphDisplayName	Optional label for oscilloscope-style graph display.	"I_LOAD"
graphCenter	Current value shown at the center of the trace display.	0.01
graphOffsetDivs	Vertical offset, in divisions, applied to the trace center.	-1
graphUnitsPerDiv	Current scale per division. For ammeters this is amps per division.	0.005
footprint	Optional footprint. Required if you position the ammeter on the PCB.	"0402"

Scope-style graph display

Use graphCenter, graphOffsetDivs, and graphUnitsPerDiv when plotting multiple current and voltage signals on the same simulation graph. These props scale the ammeter trace independently from voltage probes, so current can be shown in amps per division while voltage probes use volts per division.

<ammeter
  name="ILOAD"
  color="#8a35d7"
  graphDisplayName="ILOAD"
  graphCenter={0.002}
  graphOffsetDivs={-2}
  graphUnitsPerDiv={0.0005}
  connections={{
    pos: ".R_LOAD > .pin2",
    neg: ".V1 > .pin2",
  }}
/>