TTi PL303-B - DC Power Supply / Lab Power Supply, Outputs: Single, Voltage Output 1: Variable, Max Voltage Output 1: 30 V

The New PL Series is the latest high-performance linear regulated dc power supply range from TTi. It replaces the original PL series which has been the laboratory power supply of choice for many organizations across the world.

The New PL Series retains the true analog control of the original PL series, but combines it with new digitally based convenience features, higher power density, and superior performance.

Analog Control for a Digital World

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.

The 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 that 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 that 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 an additional adjustment of ±1%.

Once set, the voltage span function can be turned on or off at the press of a button*.

Ultra-Compact Design with Higher Power Efficiency and Near-Silent Cooling

The New PL series achieves an exceptional power density for a linear regulated power supply by offering up to 90 watts from a ¼ rack 3U sized casing. This gives it an unusually small bench footprint taking up less space on a crowded bench. For rack-mount application, up to four units can be mounted into a single 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 internal heat-sinks use fan-assisted convection cooling in order to remove the heat with minimal fan noise.

Better performance ....

• Linear regulation: ultra-low output noise and fast transient recovery
• High power density: 90 watts per output from an ultra-compact case size
• Higher precision: exceptional line and load regulation; easy-switch remote sense
• Better metering: high accuracy four digit fixed-resolution meters; low current range; current meter averaging

.... with real ease of use

• True analog controls: quick and intuitive adjustment of voltage and current
• With digital convenience: unique S-Lock and V-Span functions (see opposite)
• See exactly what’s happening: dc output switch - check your settings before applying them; ‘view settings’ button - check and adjust limits at any time
• Safe and secure to use: lockable voltage and current settings (using S-Lock); connect via safety binding-post terminals

QM Models - PL303QMD (quad-mode dual) PL303QMT (quad-mode triple)

Compact Dimensions
The PL303QMD is a dual output power supply with the same high power density as the single output models - 180 watts from a half-rack 3U sized casing (214mm x 131mm).

Four Modes of Operation
The PL303QMD is more than just two PL303 single power supplies in one box. It has four modes of operation: Independent, Isolated Tracking, Isolated Ratio Tracking, and True Parallel.

Independent Mode:
The two outputs are completely independent and electrically isolated from each other.

Isolated Ratio Tracking Mode:
As normal tracking, but the Slave voltage can be set to any percentage of the Master voltage and retains that ratio as the Master voltage is varied.

Simultaneous Output Control
The Both On/Both Off buttons are in addition to the individual switches for each output, and allow both outputs to be turned on or off synchronously by a single button press.

Synchronous switching of the outputs is of increasing importance for circuitry which can be damaged if one voltage rail is present without the other.

Isolated Tracking Mode:
The two outputs remain electrically isolated, but the voltage control of the Master output sets an identical voltage on the Slave output.

Note: Isolated Tracking enables the user to create two rails of either polarity and to reference them to different grounds if necessary (e.g. digital ground and analog ground).

True Parallel Mode:
All of the power is channeled to the Master output which can then supply up to 6 amps.

Note: In Parallel mode, the Master side becomes a single 180-watt power supply, with the current meter operating to 6 amps. The slave output is disabled and its displays are turned off.

* Safety interlocks
A key requirement in a power supply is to prevent the wrong voltage or current being accidentally applied to the circuit-under-test. Consequently, all operations that could result in an unexpected change in voltage or current settings have intelligent interlocks to prevent this.
 
** Safety terminals
The use of fixed-shroud 4mm plugs is becoming mandatory within an increasing number of laboratories for safety reasons. Standard binding post terminals can not accept these fixed- shroud plugs.