New 300W electronic load from TTi

The LD300, new from TTi, is a dc electronic load with maximum input levels of 80 amps and 80 volts. It is intended for use in investigating the behavior 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.

It has a maximum power dissipation of 300 watts, 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 1 volt at 40A and less than 2 volts at 80A.

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; the slew-rate is 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 behavior of a source to be viewed on an oscilloscope or external meter.

Each generator provides a main output with a maximum emf of 20V pk-pk from a 50 Ohms or 600 Ohms source. An amplitude vernier with a range of 20dB is combined with two switched attenuators of -20dB and -40dB to provide levels down to 2mV pk-pk unterminated.
Variable DC offset of ±10V is available via a centre detent control. An auxiliary output provides a fixed 0V to +5V level suitable for driving both TTL and CMOS loads

The LD300 is fully protected against excessive current, power dissipation or internal temperature, and minimizes audible noise by automatically controlling the fan speed according to the power dissipation.