Showing posts with label Bipolar-Transistors. Show all posts
Showing posts with label Bipolar-Transistors. Show all posts

Monday, June 25, 2012

Diodes Inc and Zetex Semiconductor Products

"Zetex is a leading provider of high performance, analog semiconductor products for signal processing and power management. Headquartered near Manchester in the UK..."Diodes Inc and Zetex Semiconductor Products

Update - Zetex is now part of Diodes Inc..

Diodes Inc and Zetex Semiconductor Products

Diodes Incorporated is a leading global manufacturer and supplier of high-quality application specific standard products within the broad discrete, logic, and analog semiconductor markets.

  • Bipolar transistors
  • General power management
  • Motor control

ZXLD1350 Evaluation Board

ZXLD1350 Evaluation Board

The ZXLD1360 provides a 1A version of the same circuit topology, whereas the ZXLD1362 and ZXLD1366 are 60V options, ideally suited for linear LED arrays (comprising Cree XPE or XPG, for example) for T8 or T5 fluorescent tube retro-fit or system replacement.

Sunday, September 04, 2011

BD139 and BD140 Complementary transistor

BD139 and BD140 Complementary transistor

This pair is my favorite when driving small solenoids or motors. SOT-32 12 Watts..

BD139 - NPN, 80V and 1.5A, 40 beta min.
BD140 - PNP, 80V and 1.5A, 40 beta min.

This means any small solenoid, relay or DC motor can be controlled with this. I would use it upto 24V DC and max of 1A for applications of full on and full off.

In applications like a regulator or variable motor control, you have to keep in mind the current thru and voltage across the transistor which results in power dissipation. Let us say it is driving 0.5A thru a motor in speed control and the Voltage across is 30V then the dissipation could be 30 x 0.5 = 15 Watts.

That is the reason we use switched regulators or switched controllers. So if we chop the DC and do PWM you have only the Switching losses and also a bit of DC loss. Switched controllers are also green, they save power for the same work done, but generate EMI-RFI and care is required in sensitive uV circuits. The transistors for switching are also special as they have to be fast with less capacitance, hence the mosfets are preferred in those applications. - ananth (san)

Monday, June 04, 2007

4QD-TEC: Electronics Circuits Reference Archive Index

4QD-TEC: Electronics Circuits Reference Archive Index|

4QD-TEC: Electronics Circuits Reference Archive.

Battery Monitoring circuits, Circuit Theory and tutorials, Component types and values, Current sensing and control, Industrial Control circuits and suggestions, Measurement Circuits, Motor Control Circuits. Power Supply circuits, Pulse (Width and position) Modulation Circuits, Relay Driver Circuits, Staircase generators, Test Equipment circuits, Temperature Measurement, Timer Circuits, Ultrasonic Circuits, Voltage/Current controlled circuits.