delabs Schematics

Perpetual Candle – White LED Lamp on Ni-Cd

admin — Thu, 15 Oct 2009 13:04:00 +0000

This is a easy to build LED lamp circuit for Learning and building skills. This is the first draft schematic V 1.0. It will need improvements for Higher Power Lighting. From Schematics of delabs I will give a short summary, The LM317 here configured for around 6.4V DC. The Q3 BC547 limits the current, you can select [...]

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Interface a uC to PC RS232 with MAX232A

admin — Thu, 08 Oct 2009 01:56:00 +0000

This is the standard configuration on how to Interface a uC like 8051 to PC RS232 with MAX232A. The UART or Serial port was not present in 8049/8749 chips which were the ancestors of 8051/8031. Pages of code were needed to make a software UART in MCS-48. The 8051 integrated the hardware UART and short [...]

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Resistance Measurement Analog LED Meter

admin — Sun, 22 Feb 2009 02:05:00 +0000

This is a LED Analog Meter, This can be used as a Resistance Meter and Low Impedance Voltmeter for Battery Levels. To measure battery voltage, the R5-R12-R17 etc. part of the Reference Resistor Divider Network can be modified to suit. Shown here is for 4 LEDs, Use Three LM324 for 12 or More LEDs and [...]

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Analog Level by BCD Thumbwheel Switch

admin — Fri, 20 Feb 2009 06:35:00 +0000

BCD Thumbwheel Switch is used to input-set data in digital form, this can be read by digital circuits, uC and uP systems and PLC-SCADA Interfaces. In the early transition of analog to digital, before uP became acceptable, Digital systems without uP were made, it even had printers, RAM and displays. The uP systems were coming in, [...]

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Opamp Supply on Buffered Virtual Ground

admin — Thu, 19 Feb 2009 11:01:00 +0000

When a Inverting Opamp Configuration is at a steady state, we say the Inverting Input is at a Virtual Ground. That means it is at 0V w.r.t to the dual power supply ground, but it cannot drive or draw any current. It is at a high impedance, but still at 0V. When you buffer this [...]

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Voltage to Frequency Converter ICL8038

admin — Thu, 19 Feb 2009 08:10:00 +0000

This was a small circuit made for driving an Impact counter. The heart being ICL8038. It must have been a Motor driving a Conveyor, the motor has a feedback attachment called Tachogenerator. Only part of the circuit is shown here. See the image of product here Tacho Counter. The configuration is derived from the Application Notes [...]

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Millivolt Source – Field Calibration Current Loop

admin — Thu, 19 Feb 2009 06:50:00 +0000

This is easy to rig millivolt source for field calibration or troubleshooting of 4-20 mA current loops. Here a Darlington pair is used for current amplification which reduces the Ib error as gain is very high. A rotary switch selects, 4-12-20 mA Preset points. A Bourns multi-turn wirewound Pot can also be used with a digital [...]

This post is a snippet, to see the full content visit this blog or http://www.dapj.net/. The blogs are listed at dapj Web.