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Showing posts with the label Mains

Digital Mains Voltage Indicator

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Continuous monitoring of the mains voltage is required in many ap-plications such as manual volt-age stabilisers and motor pumps. An ana-logue voltmeter, though cheap, has many disadvantages as it has moving parts and is sensitive to vibrations. The solidstate voltmeter circuit described here indicates the mains voltage with a resolution that is comparable to that of a general-pur-pose analogue voltmeter. The status of the mains voltage is available in the form of an LED bar graph. Presets VR1 through VR16 are used to set the DC voltages corresponding to the 16 voltage levels over the 50-250V range as marked on LED1 through LED16, respectively, in the figure. The LED bar graph is multiplexed from the bottom to the top with the help of ICs CD4067B (16-channel multiplexer) and CD4029B (counter). The counter clocked by NE555 timer-based astable multivibrator generates 4-bit binary ad-dress for multiplexer-demultiplexer pair of CD4067B and CD4514B. Circuit diagram: Digital Mains Voltag...

Mains Frequency Monitor Circuit Diagram

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Here is a simple frequency counter designed to monitor the 240VAC mains supply. It as a frequency range of 0-999Hz, so it could also be used with 400Hz equipment. Standard TTL/CMOS logic is employed for the counters and display drivers, while an ELM446 (IC1) generates accurate 1Hz pulses for gating. This device utilizes a 3.579545MHz crystal for its timebase, as commonly found in TV and video circuits and even on old PC motherboards. Mains Frequency Monitor  Circuit diagram: Mains Frequency Monitor Circuit Diagram Source by : Streampowers

Audio Controlled Mains Switch Circuit Diagram

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This is a simple Audio Controlled Mains Switch Circuit Diagram . Simple but very forkful project for audio liker circuit. This circuit will switch off the line supply to audio or video equipment if there has been no input signal for about 2 seconds. SI provides manual operation and S2 acts as a reset. This circuit allows for time to change a tape or compact disc.About 50 mV of audio signal is necessary. Read:  Solid-State Switch For Dc-Operated Gadgets Audio Controlled Mains Switch Circuit Diagram Sourced By : Circuitsstream

Remote Control Mains Switch Circuit Diagram

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This is the simple project of Remote Control Mains Switch Circuit Diagram. As the only electronics engineer in my  =family and circle of friends, it is some-times not possible to evade an appeal for help. This time the request came from a friendly elderly lady in a retirement home. In her room the light switch by the door  and the pull cord above the bed operate the light fitting on the ceiling in the middle of the room. However, she would prefer that her standing lamp was operated  by these switches instead, since she does not actually have a light fitting mounted  on the ceiling. This standing lamp has an  on/of f switch in the power cord and is  plugged into a power point. However, it  stands rather far from the bed so that she  always has to find her way in the dark. A  wireless operated power point is not really  a consideration, because it is just a matter of time before the remote is lost. Or maybe not?  Remote Control Mains ...

Simple Mains Frequency Monitor Circuit Project

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Project of Mains Frequency Monitor Circuit Diagram. Here is a simple frequency counter designed to monitor the 240VAC mains supply. It as a frequency range of 0-999Hz, so it could also be used with 400Hz equipment. Standard TTL/CMOS logic is employed for the counters and display drivers, while an ELM446 (IC1) generates accurate 1Hz pulses for gating. This device utilizes a 3.579545MHz crystal for its timebase, as commonly found in TV and video circuits and even on old PC motherboards. Mains Frequency Monitor Circuit Diagram : Mains Frequency Monitor Circuit Diagram Copyright: Silicon Chip Electronics Magazine

Battery Charging Indicator For Mains Adaptor

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Although you may well be the proud owner of the very latest NiCd battery charger, you may still come across the odd 'incompatible' battery, for example, one having a rare voltage or requiring a much higher charging current than can be supplied by your off-the-shelf charger. In these cases, many of you will resort to an adjustable mains adaptor (say, a 500-mA type) because that is probably the cheapest way of providing the direct voltage required to charge the battery. Not fast and not very efficient, this 'rustic' charging system works, although subject to the following restrictions: Circuit diagram: Battery-Charging Indicator Circuit Diagram You should have some idea of the charging current. In case you use an adaptor which is adjustable but of the unregulated, low output current type, you can adjust the current by adjusting the output voltage. You have to know if the current actually flows through the battery. A current-detecting indicator is therefore much t...