Bench power supply from TTi

In designing the new PL Series, TTi wanted to incorporate the stability benefits associated with digital control. However, they were also anxious to ensure that the product would meet customer needs and expectations.



To ensure this, the company embarked upon a series of interviews with customers aimed at discovering their preferences, particularly over front-panel controls. It quickly became clear that, whereas users understood the benefits of digital control, many saw it as unnecessarily complicated for adjusting the basic parameters of voltage and current. Traditional analogue controls were seen as simpler, quicker, and better fitted for the job.



To solve this dilemma, TTi designed a hybrid system combining true analogue control knobs with digital internal circuitry. For the user, the new PL Series operates identically to a traditional analogue controlled power supply. However, if the user wants the benefits of digital control, they are

instantly available via the S-lock and V-span functions.



The S-lock function enables the voltage and current settings to be locked at the press of a button. This transfers control of voltage and current from the analogue controls to internal digital circuitry. This offers not just complete security, but exceptional stability as well, with each setting controlled by a high-resolution instrumentation quality digital-analogue convertor.



The V-span function allows the user to redefine the end-stop values of the voltage control to create a specific voltage range. When working with any particular piece of equipment, engineers often require a voltage source variable over only a narrow range. V-Span enables the whole 300° rotation of the voltage control to cover whatever voltage range the user requires.



The new PL Series uses linear regulation to provide an extremely low RMS noise figure of below 0.4 mV with tightly specified peak-to-peak noise and common-mode current figures as well. Despite improvements in high-frequency switcher design, linear regulation still offers the lowest output noise, the best transient response and the most benign stability characteristics when driving complex load conditions.



The new PL series achieves an exceptional power density for a linear regulated power supply by offering up to 90 W from a case just 107 mm wide (1/4 rack 3U). This gives it an unusually small bench footprint for taking up less space on a crowded bench. For rack-mount application, up to four

units can be mounted into a single 3U slot.



Despite its small size and linear regulation, the new PL series generates relatively little heat through the use of an advanced phase-controlled pre-regulator. This gives it significantly higher energy efficiency than conventional linear regulated designs, particularly when supplying lower

voltages.



The first models to be launched are three single-output power supplies of 15 V/5 A, 30 V/3 A and 60 V/1.5 A, each costing £260 (plus VAT).