Building on the Success of a Winning Formula
In the 1980s the original PL series transformed customer expectations of the bench power supply and set a format that has been extensively copied by other manufacturers. Over the years, the PL series has been steadily revised and extended. Hundreds of thousands of PL series units are currently in use across the world and it remains the laboratory power supply of choice for many organizations.
TTi has been at the forefront of laboratory power supply design for around thirty years during which it has re-defined the state-of-the-art for switch mode products with its innovative Mixed-mode and PowerFlex regulator designs.
Continuing development of linear models has generated the lower cost EL series, and the advanced QL series. However, demand for the PL series has remained strong - demonstrating how well it has met the needs of its many customers. Now TTi has engineered an all-new design which retains all the key features of the original PL series, but combines them with new and important features.
Analog Controls with Digital Stability
As technology has changed, many products have moved from analog controls to digital ones. Although digital controls suit many instruments, they do not necessarily suit a bench power supply. Customer research shows that many users prefer the speed and simplicity of conventional analog controls for setting voltage and current. Digital controls may offer greater precision, but often at the expense of ease-of-use. With this in mind, the New PL series has retained the true analog controls of its predecessor.
The main disadvantage of analog controls is stability and security. The settings of analog potentiometers can drift over time. More importantly, the settings can be changed accidentally with potentially serious consequences.
The New PL series introduces S-Lock. One press of the Lock button transfers control of voltage and current from the analog controls to internal digital circuitry. This offers not just complete security, but exceptional stability as well with each setting controlled by an instrumentation quality DAC.
Linear Regulation for Ultra-Low Noise
Linear regulation still offers the lowest output noise and the best transient response (recovery time from a sudden current step). Most linear regulated power supplies offer low output noise with figures below 2mV rms being typical. The New PL series goes a stage further and an rms noise figure of 0.4mV with tightly specified pk-pk noise and common-mode current figures.
Choose a Voltage Range that Suits Your Task
When working with any particular piece of equipment, engineers often require a voltage source variable over only a narrow range. Set the voltage too high and damage might occur, set it too low and the circuit may reset. That’s where the V-Span function of the New PL series comes in. It allows the user to redefine the end-stop values of the voltage control to define a specific voltage range.
For example:
An engineer is working on a circuit that will eventually operate from four NiMh cells.
They use V-Span to set a Vmax of 5.8 volts (to prevent over-voltage damage) and a Vmin of 3.6 volts (to ensure that the circuit doesn’t reset). They now have a power supply which provides high resolution analog control over the exact voltage range they need.
Vmin and Vmax can be set anywhere between zero and maximum output voltage subject only to Vmax > (Vmin + 0.1V). The fine control gives additional adjustment of ±1%.
Once set, the voltage span function can be turned on or off at the press of a button*.