Synchronous Buck Regulator Has Constant Frequency

Linear Technology has announced a high-reliability, MP-grade version of the LTC3412A. The LTC3412A is a high-efficiency, 4MHz synchronous buck regulator that uses a constant frequency, current-mode architecture. It can deliver up to 3A of continuous output current at voltages as low as 0.8V from a thermally enhanced TSSOP-16 package.

It operates from an input-voltage range of 2.25 to 5.5V, making it suitable for single-cell Li-ion or NiMH applications and more general-purpose, fixed-rail systems. The MP-grade version is guaranteed to operate over a -55 to 125C junction temperature range. The LTC3412AMP is suitable for high-reliability applications that can experience a very wide ambient temperature range. The LTC3412AMPFE is available in a TSSOP-16E package.

Safety Brake Rectifier Emits Constant DC Voltage

The Roba-multiswitch, developed for switching safety brakes quickly, is capable of emitting a constantly controlled DC voltage, independent of the mains voltage. This means that complex adaptation of magnetic coils to varying input voltages becomes unnecessary. Overexcitation on switch-on ensures that the connected brakes release extremely quickly.

Two designs are sufficient to cover all mains voltages worldwide, from 100 to 250V AC or 200 to 500V AC, and mains frequencies of 50 to 60Hz. The Roba-multiswitch for the mains voltage range from 200 up to 500V AC is conceived for the operation of safety brakes with 104V DC coils. The constant output voltage is produced using phase segment control. When switched on, the device temporarily (0 to 50ms) emits a bridge voltage, equalling 90 per cent of the applied mains voltage, rectified to the magnetic coil.

After this very short phase, a controlled overexcitation voltage of 180V DC is applied. The overexcitation time - up to the switchover to the operating voltage of 104V DC - can be selected via DIP switch to the levels 0.15s, 0.45s, 1s, 1.5s and 2s. The Roba-multiswitch for mains voltages of 100 to 250V AC works using a controlled overexcitation voltage of 90V DC. The selectable overexcitation times remain the same. The operating voltage (coil nominal voltage) is 52V DC.

Pressure Regulators Ensure Constant Gas Supply

Dome-loaded 797 LE-HD gas-controlled pressure regulators from Witt can provide an economic and safe solution to ensure gas cutting systems receive a constant gas supply, according to the manufacturer. The company said this system of gas regulation is more economical than using a full electronic control system. In one application the three inlet lines for oxygen and propane are supplied via Witt pressure regulators to optimise the automatic gas supply.

The gas control was regulated using proportional valves with changes in the gas pressure being adjusted by pressure changes, thereby controlling the cutting process. Witt pressure regulators can be used for numerous applications with a range of flow rates and gases. They are used as a primary pressure regulator, which can be installed in any orientation, in gas supply pipeline systems to ensure a consistent stable pressure up to a flow of 2300m3/h and are independent of any inlet pressure fluctuations in the gas supplies, including gas withdrawals.

They are also suitable for use in shipyards, chemical processing plants, offshore and diving vessels, glass making as well as steel making and foundry applications. Other features include integrated pilot pressure and pressure gauge connections as well as being able to centrally regulate several gas supplies to the same working pressure, while the compact design enables them be installed in confined spaces. The maximum pre-pressure for the 737LE-HD is 240 bar with a regulating range from 2-45 bar.

Sola Hevi/Duty Constant Voltage Transformers

Sola/Hevi-Duty offers a broad range of transformers to meet many applications. These dry-type transformers are offered encapsulated, ventilated or non-ventilated, 600 Volt Class, isolation type, single and three phase, through 500 kVA. Indoor and outdoor models are available.

General Purpose Transformers can be located close to the load. No vaults are required for installation and no long, expensive feeder lines are needed. Common applications include inductive and resistive loads such as motors, lighting and heating. Hevi-Duty general purpose transformers are manufactured to meet applicable industry standards, are listed in accordance with UL 506 and UL 1561 specifications and are classified as isolation transformers. The family of transformers includes:

• Distribution Transformers
  
• General Purpose


• Low Temperature Rise


• K-Factor


• Copper Wound


• Automation Transformers
  
  
  
  • General Purpose
  
  
  • Hazardous Location
  
  
  • Buck-Boost
  
  
  • Drive Isolation
  
  
  • Industrial Control