The Load Status Indicator (LSI)

The next generation pilot/indicator light.

The Load Status Indicator unlike conventional indicators will not only indicate power but also if the load is active. The LSI is the next generation pilot/indicator that will finds its way into design applications never before possible. It will give the engineer a whole new device to design with. Unlike conventional pilot/indicators that are primary used to indicate a power on condition only, the LSI will indicate available power and if the load is actually active (drawing current).


The LSI will operate on DC and AC from 8 Volts to 240 Volts, with a supply current of 10ma regardless if operating voltage. Active current (Red LED indicating) is set for 1.5 Amp but any current from 1.5 to 30Amps can be set in production furthering the flexibility of the LSI.
The unique features of the LSI enable it to be incorporated as an integral component of a circuit breaker or switch. This would further enhance the value of both of these components giving engineers/designers options and opening up further applications.


The LSI uses a hall effect sensors to measure the magnetic field that the load generates. Designed to indicate red, an active load, if the load is drawing more than the preset amount of 1.5 Amps or green if power is available and the load is drawing less than the preset amount of 1.2 Amps. The LSI will operate on DC and AC from 50 Hz to 400 Hz sine or modified sine that is common on power invertors. The operating voltage range is from 8 Volts to 240 Volts AC or DC, supply current is a constant 10 mA regardless if operating voltage. The LSI has two 0.110 quick disconnects that can be used to operate a remote indicator (red/green) or simply connected together for a common return and two 0.250 quick disconnects for load and supply.

Designed to replace existing pilot/indicator lights the LSI is 2.0” long 0.5” round constructed for panel mounting up to 0.5” thick using the standard 15/32 x 32 electronic hardware thread with a bezel style nut that makes for a very attractive installation. The indicating element is a very high illuminated bi-state LED (red/green) that can be seen in direct sunlight. The housing is made from black derlin material which is easy to machine and exceptionally durable. The electronic assembly is epoxy encapsulated making the LSI completely protected from the environment.

Principal of Operation:

The design of the LSI is based on a current and voltage sensing circuits.


If the supply is present then the green LED will illuminate, indicating that power is available to operate the load. If the load is drawing more than 1.5 Amps then the red LED will illuminate, indicating that the load is active. When the red LED is illuminated, the load is operating somewhere between 1.5 Amps, and the rating of the circuit protection, which should be less than or equal to 30 Amps. Since the load is operating within limits it can be assumed with a high level of probability that the device (load) is operating correctly.
Another feature of the LSI is the ability to connect additional indicator/devices to the R and G terminals. This can be used for remote indicators or interfacing with computers/controls. The return current from R and G terminals to ground is a constant current of 10 mA, which is ideal for operating LED's.

To get a better understanding of the unique nature of the LSI, consider the following:

For example, a simple On/Off control running a pump in a remote location. Consider the following two circuits:


Circuit 1 uses the typical pilot light and circuit 2 the LSI. In circuit 1 the pilot light will only indicate if power is available for the pump to run. In circuit 2 using the LSI, LSI not only indicates if power is available but also indicates with high probability that the pump is running. By sensing the current that the pump is drawing the entire pump wiring circuit, including the pump is tested for proper operation. If, after the pump switch was turned on, the LSI did not indicate red, then the pump is not running and the fault condition exists. In addition, also note position of the LSI. The LSI is installed before the on/off switch, unlike the pilot light circuit which is installed after the on/off switch. In this position the LSI is constantly indicating green if power is available. This is the most effective position to install the LSI

The market potential for this LSI is enormous, finding applications in just about every industry using electrical power.

For more information about manufacturing, Licensing or purchasing this patent contact please:

Name: George Sotiriou
Phone: 631-732-1378 voice/fax