For use in investigating the behaviour of many different types of DC power sources such as batteries, solar cells, fuel cells or wind generators
The LD300, from TTi (Thurlby Thandar Instruments), is a DC electronic load with maximum input levels of 80A and 80V, making it ideally suited for use in investigating the behaviour of many different types of DC power sources such as batteries, solar cells, fuel cells or wind generators, as well as electronic power-supply units.
The new unit has a maximum power dissipation of 300W, and is designed to have very low internal resistance to allow operation at high currents with low voltage drop.
Operation down to 500mV is possible at currents up to 10A, rising to 1V at 40A and less than 2V at 80A.
The LD300 provides five different operating modes: constant current, constant voltage, constant power, constant resistance and constant conductance.
The value of the chosen constant parameter is set by 10-turn controls on the front panel.
Alternatively, an external control voltage can also be used to set the level of the load.
Any desired waveform can be applied, allowing complex load conditions to be simulated.
An internal transient generator can repeatedly switch the load between two different operating levels set on separate 10-turn controls.
The frequency and duty cycle of the transients can be set over a wide range.
The transients can also be initiated by an external logic signal.
The transitions between the levels have a true linear slewing characteristic in all modes, with the slew rate adjustable over a wide range.
A low-voltage dropout facility is provided to protect sources such as batteries from damaging levels of discharge by reducing the load current when the source voltage falls below the dropout threshold.
Load conditions are displayed using high-accuracy four-digit meters.
The voltage of the source can be sensed either internally for convenience or externally for better accuracy.
A current monitor output provides a voltage proportional to the current flowing, allowing the behaviour of a source to be viewed on an oscilloscope or external meter.
The LD300 is fully protected against excessive current, power dissipation or internal temperature, and minimises audible noise by automatically controlling the fan speed according to the power dissipation.
The unit is housed in a compact case measuring 130x212x435mm (half rack width, 3U height) with a weight of 6kg. The LD300 costs £695 (plus VAT) in the UK.
