2008 September » delabs Tech

DC Regulated Power Supply

Instrumentation, Power Electronics No Responses »

Sep 252008

This is a Regulated 0-30 V DC Power Supply manufactured by me in small numbers, 0-30V 5A and 5V -5A. It had a Switching Preregulator. This keeps the Vce across Transistor Bank at the Back of Instrument, at the lowest possible level, in order to keep them Cool. When Vce and Ic both are more in a Power transistor it will get heated more, then the efficiency of power supply is low. The Output had both Constant Current Control and Constant Voltage Control. The CC control is also a Short circuit protection. The Output was protected from outside voltages damaging [Read More ....]

Transformers Series and Parallel Connections.

Electrical, Power Electronics No Responses »

Sep 242008

Series and Parallel Transformers Series and Parallel Connections in transformers. Observe the Dot-Polarity. When windings are in parallel the current capacity doubles. When windings are in series the voltage doubles. Wrong dot polarity in series connection just cancels the voltage and a small residual imbalance voltage remains. If wrong polarity connection is done in parallel, then a short circuit or overload may occur. Center Tap Transformer This is when you need to build a symmetrical dual supply like +12V and -12V supply for an opamp design. This is also good for a two diode full wave rectifier. But when you [Read More ....]

Embedded Computing using Google Android

Embedded, Mobile Handheld No Responses »

Sep 242008

Small Device Embedded Computing is now a lot easier, with a ready to use Google Android Code. You can probably make, small intelligent networked devices for automation or even use it for Autonomous Self Learning Fuzzy Robots. Open Handset Alliance Android is a software stack for mobile devices that includes an operating system, middleware and key applications.Integrated browser based on the open source WebKit engine “… a group of more than 30 technology and mobile companies who have come together to accelerate innovation in mobile and offer consumers a richer, less expensive, and better mobile experience.” Learn more about the [Read More ....]

PLC based PID Controller

Process Control No Responses »

Sep 242008

Below is a Electrical Control Panel, It has a Strip Chart Recorder which is electro-mechanical, It has a PLC Inside. A handheld PLC Programming unit. The computer is showing the Ladder Logic Program. PLC is based on a embedded uC. The DIN Controllers are Analog + Digital circuits. So you see it is a Electrical Control Panel with Electronics and the PLC Ladder Logic means, Software too. This is a PID Controller based Control Panel using a PLC from GE Fanuc Automation. The Computer is a 386 40MHz with 40MB HDD.

Multizone Process Scanner

Design, Process Control No Responses »

Sep 232008

This could take current or voltage inputs from many remote transmitters, 4-20mA or 0-1 V Inputs. Then it would display the calibrated value in a LED display. The Zone number was a digital display. This serves as a monitor of process values. It had a analog output with a digital channel byte-word output for interface with other instruments. This uses the CD4051-52 for the analog switching. Operating this at +/- 7.5V gives best isolation from channels and low ON resistance. Now you have many types of devices to do this. When a large area or object has to be heated, [Read More ....]

Analog Blind Dial On Delay Timer

Process Control No Responses »

Sep 232008

It is called analog dial timer as it has no digital display, but the chip is digital it is CD4541. It is Mains operated, you could make on-delay or off-delay. By changing the caps and resistors or with even dip-switches you could get timing of few seconds to many hours. Circuit is Analog Timer 4541 pdf . Some timers energize the relay after a set delay on power start. Some start with relay energized and turn off after set time. Motors and big systems cannot take fast turn-on and turn-off, Some systems will require sections or modules to start one [Read More ....]

Water or Fluid Level Sensor Alarm Control

Process Control No Responses »

Sep 232008

Water or Fluid Level Sensor Alarm Control

This is a way by which you can monitor the level of fluids like water in a tank. Based on data from the sensor you can control things like solenoids or motors as required or even turn on a buzzer, hooter or annunciator in a control panel. Description. Look at the picture on the right, the float can be a Styrofoam type with a couple of ceramic magnets stuck inside. The float must move freely up and down a long plastic pipe of around 10 mm dia. If the fluid is not water but a solvent then design a non-soluble [Read More ....]

Hobby DIY Garage

Basic Electronics, Gadgets No Responses »

Sep 222008

Hobby DIY Garage Hobby and Do-It-Yourself Projects, DIY Electronics, Gadgets News. Amps-n-Volts html Newsletter which later became Amps Volts eMag on WordPress. It is now Hobby DIY Garage. Strictly Hobby, Gadgets and Craft with greater weight for electronics hobby. dapj Web

Sequential Timer – Pressure Switch

Design, Process Control No Responses »

Sep 222008

This was built in a 96 X 96 Cabinet. It takes the process thru three timer delays and the pressure is measured after a certain stage and at a setpoint the process, job or DUT passes or Fails. It could be stress, strain or load testing on object. User Manual – Sequential Timer – Pressure Switch Related Resources Two Stage Sequential Timer – del90004 Sequential Timer – 555 – PDF Some Cyclic Timer Links Simple Sequential Circuit -State Machine Synchronous switching of multiple electrical devices