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Wednesday, November 16, 2016

Temperature control for CPU

My name is IS and I am looking for somebody to design and build a simple circuit that controls a small computer fan using either a 120V plugin or a battery using a temperature switch...

In other words I would give you the set point and at that temperature it would turn on the fan and when it drops below the set point it turns off the fan.. the temperature would have to be measured using a contact type measuring device like a thermocouple or thermistor.

Mail from IS Brazil

Go thru these links and visit all pages -
 Try this One Chip solution from Maxim Semiconductor

MAX6641 temperature sensor and fan controller

MAX6641 temperature sensor and fan controller

"Accurately measures the temperature of its own die and the temperature of a remote pn junction. The device reports temperature values in digital form using a 2-wire serial interface. The remote pn junction is typically the emitter-base junction of a common-collector pnp on a CPU, FPGA, or ASIC."

Some of my circuits are here Industrial Process Control Circuits

    Decade Digital Counter Module - LED and LCD

    I'm looking for a source of decade counters and wonder if you can help? I don't want to build the counter, I want to buy a functioning counter module.

    Do you have source suggestions?

    Mail from SF USA On 1/1/2011 1:34 AM

    Try These, some are kits, some ready modules.

    delabs has a resource on counters -   Digital Timers Counters and Clocks

    Easy way to build a counter since the 80s is using ICM7217.

    4-Digit, Presettable, LED Up/Down Counter

    4 Digit Counter Module - The counter module is supplied pre-assembled and tested and provides the building block for counter and timer circuits. 

    The counter module may also be used as an accurate digital timer with the addition of a suitable timebase and gating circuit.

    4017B Decade counter (5-stage Johnson counter) - Learn about the 4017 by building the DOCTRONICS Light Chaser Project:

    Multifunction Counter-Timer Electronic Kit K8035 - Counter-timer K8035 is a multifunction electronic kit that is handy for all sorts of counting and timing applications. Counts up or down from your own pre-defined starting point. Counter-timer can count each time you press the onboard push buttons, or count externally supplied voltage pulses.

    VM147 - Panel Counter MODULE - offers a very practical solution for counting parts, people, scorekeeping, etc.

    LCD counter module 7016 6-digit - Snap-fit module with 4-digit LCD and its own power supply (not included). This counter module is therefore suited to PCB-mounting (snap-in frame can be removed) as well as front-panel mounting

    Try Radio Shack ask for - LCD Counter Module - it may be expensive compared to above.

    Tuesday, November 15, 2016

    Three Phase AC SSR for 1 HP Motor

    I need to build a three phase AC(in 120V)-AC(out 440V) solid state relay to turn on or off a small(1hp) three phase AC motor. Do you have any idea?

    Can I use three MOC3043 and three TIC236E triacs of course with all opto LEDs in series?

    Mail from FJP Brazil

    See my SSR Circuits , Solid State Relays or SSR Choose a DC Control and AC Load SSR, That is what you seem to indicate.

    1 hp = 745.699872 watts

    Let triac have 10 A and 600V AC ratings, BTA12600 But now BTA12600 is obsolete, adapt to what is available in your country.

    MOC3043 is fine, isolation must be good, take care. Use a Heatsink.
    ON-OFF Control inputs can be parallel not series.

    Here is a picture of a Solid State Contacter from Power IO

    Three Phase AC SSR for 1 HP Motor

    On this page you can see a 3 phase SSR i built. Three-Phase-SSR.