Electronics for Dummies - UK Edition

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Now suppose, if a few of the appliances are switched OFF, this would create a low pressure on the generator forcing it to spin faster and generate more electricity. The heart of the circuit is the IC LM3915 which is basically a dot/bar LED driver used for displaying variations in the fed analogue voltage input through sequential LED illuminations. When it comes to LM358 in particular, it’s not a rail-to-rail op-amp, hence its voltage levels will be throttled. Actually, LM358 allows its inputs to go down to the negative rail, but does not allow the inputs to get closer to the positive supply rail than 1.5V (i.e. 3.5V @ 5V VCC). Further, there’s a drop in the output voltage (usually 1.4V,). Under this situation if a few of the appliances are switched OFF would relieve the generator from some load resulting in an increase in its speed, however the increase in the speed would also create an proportionate increase in voltage at pin#5 of the IC.

Circuit basics— learn what voltage is, where current flows (and doesn't flow), and how power is used in a circuit Feel better every day. That is the motto of Tunturi. Our origins lie in Finland, where two brothers started a bicycle shop in 1922. Now, over 100 years later, we are a Dutch company and a global brand. We support you on your journey to a healthy and fit body, a balanced mind, and a happy life. We do this with a wide range of cardio and strength training devices, accessories, and supporting apps. It’s a range that is constantly expanding and improving, with quality products and excellent guarantees. Can't find your way or do you have questions? Our service team is ready to assist you. Now suppose the rotational speed of the generator drifts towards the higher side, would create an equivalent rise in potential at pin#5 of IC2 which in turn would give rise to higher mark ratio to the mosfet, allowing it to conduct more current to the load. The load input voltage is limited mainly by the drain to source voltage (Vds) rating of the MOSFET, and current by the value of current sense resistor. Take note, while connecting the source to the load, you should calculate the power dissipation carefully to retain the MOSFET always in the safe operating area (SOA) otherwise it will be deep-fried as soon as its die temperature exceeds the safety margin. Since the above mentioned devices work only with DC, the generator output is suitably converted to DC via 10amp diode bridge for the required switching.

This is in fact rather straightforward, it's all about employing a circuit which monitors the voltage of the generator and switches ON or OFF a few dummy loads which in turn control and compensate for the increase or decrease in the speed of the generator. For loudspeaker simulation, a more complex network is more accurate, however, as actual loudspeakers are reactive and non-linear. There are many designs for loudspeaker simulators, which emphasize different characteristics of the actual speaker, such as the voice coil's inductance, mechanical suspension compliance, and cone mass. I work for a Power electronics industry manufacturing motor drives and UPS systems upto 45 KW 3 Phase. The above operations become necessary because the concerned generator may be driven by an irregular, varying source such as a flowing water from a creek, river, waterfall or through wind. Additional two resistors R8 and R9 are used to sense the supply voltage of the power supply that will be stressed by this dummy load. As per the voltage divider rule, these two resistors support a maximum of 24V. More than 24V will produce a voltage that will be not suitable for the Arduino pins. So be careful not to connect power supply that has more than 24V output voltage.

Now these LED pinouts (from LED#2 to LED#20) are also attached with individual dummy loads via individual mosfet drivers, in addition to the domestic load. Ohm’s Law and Joule’s Law are commonly used in calculations dealing with electronic circuits. These laws are straightforward, but when you’re trying to solve for one variable or another, it is easy to get them confused. The following table presents some common calculations using Ohm’s Law and Joule’s Law. In these calculations:

SWITCHING NOISE

The resistance which is responsible for influencing the triac conduction is substituted by the LDR inside the opto assembly, meaning the LED brightness levels now becomes responsible for adjusting the triac conduction levels. Thanks for reply and I was out of country for two weeks. Thanks for info and timer circuit is working very fine now. As we all know that for many appliances are such as refrigerators, ACs, motors, drill machines, etc voltage and frequency can be crucial and may be directly related to their efficiency, thus any change in these parameters cannot be taken lightly.

When in standby mode, the threshold voltage & the load current can be set. Here the Amps LED is lit, so the load current can be set. The pair of LEDs between the displays shows which digit will be changed. Pressing the encoder button cycles through the options. Volts Set

Calculating the RC time constant

The above calculations clearly show that the RPM, frequency and voltage of the generator are extremely linear and proportionate to each other.

Martin Rowe (2005-12-01). "Loads need calibration, too". Ensuring power supply accuracy. Test and Measurement World. The lamps could be 200 watt rated, 500 watt rated or as preferred by the user, and the generator specs. Circuit Diagram In the proposed electronic load controller circuit the same concept is applied, however here the pot is replaced with an opto coupler made by concealing an LED/LDR assembly inside a light proof sealed enclosure. Using Dimmer Switch as ELC I wanted a variable load for testing small dc power supplies and tried many rheostats but they are beefy, clumsy and very expensive. So I decided to build a little variable dc load that would imitate a resistive load and that would also work as a portable device. After a bit of work, I came up with this astoundingly simple hardware solution. Here is the schematic of my simple electronic dc load, realized with a handful of inexpensive and easily available components. Electronic DC Load Schematic v1

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If a MOSFET with a RDS of 10 milliohms switches a 10 ohm resistor on and off, then the resistor will get hot and the MOSFET will stay cool. But why would you want to do this? The MOSFET is cheap. The resistor is expensive. Why are you reducing the power in the cheap part so you can dissipate it in the expensive part? If you use PWM, you need other parts as well - you need big electrolytic capacitors to average the load voltage, and probably inductors to smooth the current.