Schoodles

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Amplify uV from Sensors to mV levels for A/D Converters, which in turn may drive a display or connect to a uC means MicroController.

I have my own human interface and memory limitation. I am like a 8086 based nobody’s computer in a Penta-Core 5 Ghz Fiber-Computing World, add a 5 Teral Byte HDD. I am Obsolete, i am Legacy.

Now getting back to Bizness, the inputs from the world we interact are analog, A uV level from a Strain Gauge to measure Weight/Pressure; mV from a K Type Temperature Sensor or mV from LVDT Displacement Transducer to Gauge measure linear displacement. All these Low voltage/current, AC/DC need some signal conditioning and special construction – FOR – Amplification, Attenuation, Noise/Pickup Immunity/Rejection, Linearizion, Isolation and Transmission (long wire/wireless).

Thermocouple Amplifier Standard

This means take a small signal sample in the best possible way. The Sensor/Transducer shape and sensing/converting element/technology is chosen/developed. This low mV/uV is then Amplified/Cleaned and Transmitted.Some steps like Linearization can be done by software not all steps. Now we have a nice 0-10 V or 4-20 mA Signal which any A/D with process enthusiastically. The Digital signal will be eagerly processed by a uC with firmware, without batting a eyelid or like the kids say “look no hands” (then its plaster of paris for a few weeks).

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A Low cost A/D with a Potential of 5KV Isolation from Computing elements by use of Normal/Special Opto-Couplers. This can give better resolution and accuracy than a 8 bit A/D. may be close to 10 bit A/D. Added advantage is that you can optically isolate the inputs.

Convert Analog to Digital with a V-F

Suppose your temperature sensor touches a heating element OR your speed sensor is subjected to a shock from a defective motor with earth line broken. Such situations happen in the field, even at home or lab. Sometimes it is carelessness, other times it is wear-tear. Many times it is breakdowns, accidents etc. So do not let the High voltage to get at your Microcontroller Board.

More about Embedded Micro here – Hyper Embedded

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There are places like your Backyard, outdoors, a village… where your Gadgets will stop working !!!

You will feel suffocated when your Smartphone or Tablet fails to respond to your caring strokes. Your Dupey is perishing due to Undernourishment. All you need is “Electronic Solar Umbrella” which was invented by me delabs on June 1st 2014.

Electronic Solar Umbrella

The Red Light is for Data Networking SmartUmbrellas using Advanced Multi-Threaded Infra Red Technology.

SUN – Smart Umbrella Networking

I just invented the SmartUmbrella – My Drone is Rushing to the Patent Office.

(Keep this confidential till my drone returns safely, the beagle boys are using Blimps with Large Magnets to capture Drones.)

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I got a strange problem as i added more and more peripherals, the pc gave odd messages, “i cannot detect what you are doing” and things like that. I almost flipped trying to locate the culprit. The problem was not in any peripheral but in the USB port powering the system itself. The SMPS was not loading much. Certainly the peripherals were drawing more and the warning could have been more like “use your own power”.  Computer Data Interface

Powered USB Hub Help PC Interface

I could not locate a powered USB with any vendor close by, so i built one and it works perfectly, Now it doubles up as a UPS Low Batter Indicator, by rare coincidence. If the Unregulated DC is above 7 volts, then no bugs. When i adjust the unregulated DC to the 7805 to around 6.9V, then i have a advance warning system.

Wireless USB – Wireless Extension to USB

USB Hub with Power

When power fails, i keep working and listening to music from a Flash Thumb drive. When music stops, i turn of computer, the lead acid batteries gone below 20 V DC. This avoids deep discharge of my batteries. The Powered USB gets undetected when the supply falls below 4.5 probably.

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This is a simple charger you can build for devices. It can be modified for any device. This may need no modification for devices that are charged using PC USB port.

Power Electronic Circuits

Charger for Portable Devices

This is a Schematic Doodle called Schoodle. Use it for Learning and understanding. Build and test only when you have practiced and gone beyond simple electrical and electronic circuits. Mistakes can damage your portable device or even waste your components. Hence take care, work systematically, not like me. See the mess i have created below.

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This is another LED lamp from China a firm called Hoya, these people make nice lamps and also good designs of the plastic enclosure. Here by a clever enclosure design it is both a emergency mains bulb and Torch/Flashlight.

The price is low and they use a small sealed lead-acid battery worth 4.5 V and around 1 AHr. That means it could give an hour of performance at 1 A drain/usage. The voltage by the elapsed hour could be near 4. Here the battery failed, vibration or leakage; OR combination of both. The acid, very little or even corrosive vapor has eaten the copper wire of positive wire/junction. The Cut Red wire, broke circuit equilibrium and burnt the R? = 3.3K – 4.7k ?. The lamp failed all other parts intact.

From Schoodles

How it works ?

It uses a step-down cap, this is very tricky. It has to be a HV cap overrated and excellent quality. These caps not good enough. I am partially responsible for this cap idea spreading around. It was decades ago in relation to bringing down the cost of industrial. automation timers. The transformer had to go and smps solution too much; a resistor inefficient. I was triggered by the choke used in tubelights to bring down voltage after firing. So if L can be used, then even C for low currents, no heat wasted. The timer worked, successful sales. Idea/Concept became popular. This idea also misused by others to save cost. This design needs an Axial Polycarbonate/Polypropylene 630V/1KV cap for reliable operation.

Now this 18 LED array, has no current limit, is it not quite a problem. The chinese are innovative on saving cost, here its fine, but.many times we can sacrifice quality. In this design the LEDs drop around 3.3V and the Transistor 1 Volt as it is not driven to saturation. On full load the battery also deregulates, so it does manage to save itself. This transistor also serves as a mains detector along with the 1N4148. On mains failure the LED lamp turns on Automatically.

Another Lamp had a Burst out 100uF cap this means, surges or spikes are damaging the 1uF 400V Plastic cap used for current limit.

Recommendations to such Lamp Designers

Use Metalized Polypropylene MPP – rated for 440V AC continuous working. That means it must be rated like a Power Factor correction/saving capacitor. It may mean 1KV DC operation.

  • Use an Axial 1uF polypropylene 630V DC or 440V AC Capacitor
  • Sell it with a Marketing Advantage as Power Factor Compensation.
  • Use two 2.2uF 630V DC Axial MPP, one on Live and the other on Neutral.

A house using Motors and Fans will have inductive elements, even tubelights that have chokes 50/60 Hz kind. This is compensated by capacitive loads. So each of these Capacitor LED lamps can be a Green Lighting and PF compensator.

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I fixed a China Torch with New LEDs and a Diode, it failed probably on a drop shock, the battery wire cut … then when put on charge Few LEDs went bad, as battery was absent in ckt.

design review – 1.5uF voltage rating can increase like 440V AC. A current source with low dropout voltage would be great but it builds the cost. The wiring has to be robust. A diode added to keep LED current within some limits on batt overcharge.

From Schoodles

These type of Torches and Lanterns should not be Turned on when charging. This may blow the LED Array.