Master / Slave Power Saving Powerboard

CitizenCane on 18/12/2019 - 01:13
Last edited 18/12/2019 - 01:15

I'm looking for a Master / Slave Power Saving Powerboard similar to this one: (https://www.jaycar.com.au/master-slave-powerboard/p/MS4081)
It was only $4.91 @ Jaycar, but they're out of stock.
I found this one on eBay for $30 (https://www.ebay.com.au/itm/153361781703) It's my only option at the moment, but I'm sure there must be more out there.

Apparently Bunnings, Dell and a bunch of other retailers used to sell them, but despite exhaustive searches I can only seem to find those two currently listed online.

They're typically used to stop power draw from devices on standby when you switch off your TV, but I actually want to use it to power on/off a vacuum when using a saw, so the ones that switch off the slave device after 60 seconds / 1 hour etc aren't really suitable.

Does anyone know where I might be able to pick one up, preferably relatively cheaply?

Electrical & Electronics

Comments

  • 299792458 on 18/12/2019 - 07:37

    They seem to have gone out of fashion, my local power company gave me one a few years back as part of a home energy audit, but now they say they are no longer made and I had to get new old stock off eBay https://www.ebay.com.au/itm/Embertec-Smartswitch-Standby-Pow…. Unfortunately for your purposes it still takes a couple of minutes to switch off the slave devices.

    • CitizenCane on 18/12/2019 - 10:15

      Yeah I looked at one of the them, apparently they gave out 1000 of them for free in Adelaide or Brisbane. I think you can set them to turn off for after 5 seconds / 1hr / 2 hr or something like that. Not ideal. Good for your home entertainment setup though.

  • Skramit on 18/12/2019 - 08:02

    but I actually want to use it to power on/off a vacuum when using a saw

    lul wut

    pls explain!?!

    • CitizenCane on 18/12/2019 - 08:12
      +2

      Most Circular Saws etc have an attachment for a Vacuum hose to suck up all the sawdust as you're cutting.
      If you're cutting MDF etc the dust is actually quite toxic.

      The only difference between these two Vacuums is one has a power plug for your saw so it will automatically turn on/off when you're using it:
      $99https://www.bunnings.com.au/ozito-1250w-20l-wet-and-dry-vacuum-with-power-take-off_p6290513
      https://www.bunnings.com.au/ozito-1250w-20l-stainless-wet-an…

      • Skramit on 18/12/2019 - 08:12
        +1

        Why do you need a fancy powerboard for that though?

        • CitizenCane on 18/12/2019 - 08:15
          +2

          So you don't have to turn on/off your Vac every time you want to make a cut.

          • Skramit on 18/12/2019 - 08:16
            +1

            @CitizenCane: I see.

            Carry on then.

          • dotMonkey on 18/12/2019 - 08:43
            +2

            @CitizenCane: I've always wondered why you'd ever use a master/slave powerboard. Thanks to your example, now I see many uses

            • CitizenCane on 18/12/2019 - 08:47
              +1

              @dotMonkey: Yeah now that I'm thinking about one for the saw I want to buy another one for my PC to turn off my speakers that I always forget to turn off.

            • Bargain80 on 18/12/2019 - 10:30

              @dotMonkey: I use them one for the TV and one for the computer.

              When the TV is off, all the related appliance will be off too, e.g. blue ray player.

              Same as computer, I connect the printer, speaker, monitor to the slave socket.

              I have also been searching for a new one but couldn't find at Bunnning.

              • CitizenCane on 18/12/2019 - 10:50

                @Bargain80: They're almost impossible to get nowdays, that ebay one I linked is one of the only ones I could find.
                I think the wifi smart power boards have replaced them all.

      • jackinyourbox on 18/12/2019 - 09:40
        +1

        Woah! Creative. I didn’t think of that one

  • CitizenCane on 18/12/2019 - 08:15

    Most Circular Saws etc have an attachment for a Vacuum hose to suck up all the sawdust as you're cutting.
    If you're cutting MDF etc the dust is actually quite toxic.

    The only difference between these two Vacuums is one has a power plug for your saw so it will automatically turn on/off the vac when you're using it your saw:
    $99 (https://www.bunnings.com.au/ozito-1250w-20l-wet-and-dry-vacu…)
    $65 (https://www.bunnings.com.au/ozito-1250w-20l-stainless-wet-an…)

    So I'd be paying an extra $34 just for a few bucks worth of electronics. I'd rather save the money and have it controlled by a power board.

    • ESEMCE on 18/12/2019 - 10:17

      I have the Ozito with Power socket. They come on sale periodically and it works well .
      You're looking at $30 ish for a powerboard anyway and those powerboards (at least the ones I have on my TV and Amp have a 10-15 second delay before switching off.
      The Ozito switches off after only a few seconds which is more suitable for your requirements.

      • CitizenCane on 18/12/2019 - 10:19

        Yeah I'll probably just pay the extra cash and buy that one. I'm just too tight, I really only need the $50 12 ltr version so moving up to $100 for the one extra (cheap) feature offends my frugal nature.

  • apsilon on 18/12/2019 - 08:40

    If Youtube has taught me anything it's that you should have Festool saw and vac that have this function built in.

    Or you could see if this is actually available though there's no mention of how quickly it turns on/off: http://www.cits.net.au/en/power-saver-master-slave-power-boa…

    • CitizenCane on 18/12/2019 - 08:42

      Cheers for that, hopefully it's instant.

      • apsilon on 18/12/2019 - 08:54

        If it works let me know, might grab one myself. Ideally you'd want the vac to keep running for a few seconds to clear the hose so as long as it doesn't take minutes to turn off and comes on within a couple of seconds it should be OK.

        • CitizenCane on 18/12/2019 - 08:56

          The Vacuum motor keeps spinning for a few seconds after you turn it off anyway so I figure that will be enough.

  • pjetson on 18/12/2019 - 08:47
    +2

    want to use it to power on/off a vacuum when using a saw

    Both a saw and a vacuum are high power devices, and particularly draw a lot of power at switch on. I really doubt that master/slave powerboards would be rated for that kind of power - I'd expect a bang.

    • CitizenCane on 18/12/2019 - 08:51
      +1

      I'm sure they can handle it if it's a decent quality power board.
      Toasters, kettles, toaster oven all use more power (around 2000w) and people often have all 3 running off one powerboard.

      • fantombloo on 18/12/2019 - 09:08
        +2

        6kW on a standard outlet is way too much and should be popping a breaker on the powerboard, and if not then in the distribution box.

        • CitizenCane on 18/12/2019 - 09:12
          -1

          More likely in the distribution box.
          One thing most people don't realise is that all your power sockets are connected to the one circuit (or maybe two in a large house) at the the distribution box anyway.
          So there is literally no difference between having all your devices connected to one socket through daisy chained power boards, or spreading them out over the whole house. The breaker is there to prevent a short, not too much power draw. People worry far too much about power boards.

          • fantombloo on 18/12/2019 - 09:20
            +4

            @CitizenCane:

            the one circuit (or maybe two in a large house) at the the distribution box anyway.

            That's not right.

            So there is literally no difference between having all your devices connected to one socket through daisy chained power boards, or spreading them out over the whole house.

            No. In the first case one GPO carries the entire load and will have localised heating, over and above the second case where the cables in the circuit are heating up within the walls, sometimes spread over longer distances. Neither situation is good, the first less so. A circuit typically is designed for 20A, an outlet for 10A.

            • CitizenCane on 18/12/2019 - 09:22
              -1

              @fantombloo: The heating doesn't occur because of how much power is running throughout the cables, the heating only occurs when there is a connection between the positive and negative. This is why High Voltage power lines aren't hot. If they were every bird would have burnt feet :)

              • fantombloo on 18/12/2019 - 09:25
                +4

                @CitizenCane: Heating is a direct (squared actually) function of current, which is proportional to the power at a given voltage (240v in a residential case).

                • CitizenCane on 18/12/2019 - 09:26
                  -1

                  @fantombloo: And the current only flows when there is a connection between the positive and negative. If what you're saying was true every power outlet would be constantly leaking power even with nothing connected.

                  • fantombloo on 18/12/2019 - 09:29
                    +2

                    @CitizenCane: Your load (saw, vacuum) is the thing connected between the terminals (not pos and neg but active and neutral).

                    You are now showing a clear lack of knowledge about all of this.

                    • CitizenCane on 18/12/2019 - 09:31
                      -1

                      @fantombloo: Active and neutral IS positive and negative.

                      • fantombloo on 18/12/2019 - 09:32
                        +2

                        @CitizenCane:

                        Active and neutral IS positive and negative.

                        You are ignorant.

                        • CitizenCane on 18/12/2019 - 09:32

                          @fantombloo: So what power outlets actually have 5 connections, +ve, -ve, active, neutral and earth?

                          • fantombloo on 18/12/2019 - 09:35
                            +2

                            @CitizenCane: None that I know of.

                            Look for a primer on AC and DC, maybe on YouTube or Wikipedia. Then on ohms law. Then on basic electricity distribution. I'm happy to converse further about it if you are open, but not like this.

                            • CitizenCane on 18/12/2019 - 09:38

                              @fantombloo: I was a telstra line tech, I know about basic electrical theory. Active and neutral and positive and negative are just two ways of describing the same thing.

                        • abb on 18/12/2019 - 09:38
                          +1

                          @fantombloo: @thevofa - There might be a misunderstanding relating to having many devices plugged in but not in use. Obviously 100 toasters on a power board will cause no heat if they are all off (as I am sure you know). It's still a bad idea because one day someone might turn them all on.

                          @CitizenCane - I'm afraid active & neutral are the correct terms, and are definitely not equivalent to positive and negative.

                          • fantombloo on 18/12/2019 - 09:42
                            +1

                            @abb: Cane has no idea. Power flowing, power leaking, active is positive - it's all just so wrapped up in heresay rather than an understanding of the most basic concepts.

                            • CitizenCane on 18/12/2019 - 09:43

                              @fantombloo: Power leaking would trigger a short at your distro box. It IS a short. I don't know where you learnt your electrical theory but you have some funny ideas.

                          • CitizenCane on 18/12/2019 - 09:48

                            @abb: "I'm afraid active & neutral are the correct terms, and are definitely not equivalent to positive and negative."

                            Yeah you're right again but because I worked exclusively in DC, not AC, I just got used to calling active positive and neutral negative. To me they are the same thing but I know technically they're not, but everyone knows what you're talking about (besides thevofa) when you say +ve and -ve relating to AC.

                            • sheamas88 on 18/12/2019 - 14:28

                              @CitizenCane: DC positive and negative are in no way equivalent to AC active and neutral. You clearly have no idea how mains power works.

                          • sheamas88 on 18/12/2019 - 14:39

                            @abb: @thevofa isn't confused, this whole thread started because the top-level comment stated OP probably couldn't run the vacuum and saw AT THE SAME TIME. OP is the one that drew the equivalent to having multiple unused devices on one powerboard, but that is irrelevant since that is not what this situation is.

              • abb on 18/12/2019 - 09:27
                +2

                @CitizenCane: I wasn't gonna weigh in on this issue, but

                heating only occurs when there is a connection between the positive and negative.

                This is wrong.
                If this were the case, all house wiring, car wiring, welding cables, etc, would be as thin as the wires to your headphones. We wouldn't need fancy 105 degree insulation on wires to lights, and half of my job would be obsolete.

                Wires absolutely heat relative to the current flowing through them (squared!).

                You are correct that the heating is not related to power.

                Source: I have a shiny certificate that took me years to get and cost tens of thousands of dollars.

                • CitizenCane on 18/12/2019 - 09:30

                  @abb: Yeah you're talking about resistance though, right?
                  That's just about having cables thick enough (ie: less resistance) to handle the maximum power flow when there is a connection between +ve and -ve.

                  • abb on 18/12/2019 - 09:33

                    @CitizenCane: Yes.

                    P = I^2 R
                    Power = current squared times resistance.

                    Resistance of wire is above zero. Therefore, current flowing in wire means power is dissipated in the form of heat, in the wire.
                    Resistance is rarely a limiting factor from an electrical point of view in wiring. It's usually heat that drives you to buy a bigger wire.

                    If you're referring to having 4 toasters on a power board and only ever using one at a time, sure, no problem. As you correctly say, current flows only when a circuit is completed.

                    • CitizenCane on 18/12/2019 - 09:34

                      @abb: Tell that to thevofa. But yeah you're right it's just that as far as I was aware, resistance is never a problem in household wiring or powerboards because the wires are sufficently low resistance (with lots of headroom)

                      • abb on 18/12/2019 - 09:54

                        @CitizenCane: So, when we talk about resistance in a wire (or socket, switch, etc) being a problem, there are a few things to consider:

                        1. Is the voltage still high enough to run your device?
                        2. Will something melt / catch fire?
                        3. Efficiency
                        4. Cost

                        AS3000 & AS3008 (and probably others, I'm not an electrician) cover the details of selecting wires to install and they do a good job in balancing the technical requirements against cost.

                        In a decent installation, circuit breakers will trip before we get dangerous heating. Voltage sag is also possible under an overload condition, but the circuit breaker will trip before you notice your toaster isn't getting as hot as it should.

                        This is enough of my time spent on this issue that I could be billing paying customers for ;)

          • sheamas88 on 18/12/2019 - 13:15
            +1

            @CitizenCane: That is completely wrong, a standard home GPO is rated for 10amp, which at 240V is 2400W. Running 6000W through that GPO is WELL above it's spec and is not the same as running them on the same circuit at all.

            Most decent powerboards would trip if you tried to draw more than 2400W through them so people don't fry their outlets.

      • abb on 18/12/2019 - 09:22

        I'm sure they can handle it if it's a decent quality power board.

        …

        $4.91 @ Jaycar

        Quality or $5, choose one ;)

        I suggest just paying for the vacuum with the feature built-in. $99 is not a terrible price for a workshop vac.

        An alternative would be to use wifi controlled sockets (I think this is why those master/slave boards have disappeared, the wifi controlled ones can do more tricks)

        • CitizenCane on 18/12/2019 - 09:24

          "Quality or $5, choose one ;)"
          Haha yeah well it was $40 but got reduced because it was discontinued.
          I'll have a look into what features those wifi controlled power boards have

      • pjetson on 18/12/2019 - 11:00

        I'm sure they can handle it if it's a decent quality power board

        The master/slave switching electronics may not be rated to detect and switch the kind of loads that are being discussed. These devices are usually intended for lower power loads, like TVs and entertainment systems.

  • c64 on 18/12/2019 - 09:37

    It was only $4.91 @ Jaycar, but they're out of stock.

    yeah, you can list it for any price you want when you've got no stock

    I actually want to use it to power on/off a vacuum when using a saw

    generally the load that can switched is quite low, 500w? you need to check that whatever you buy will switch your load

    • CitizenCane on 18/12/2019 - 09:40

      I don't think so, the problem was the power draw to keep the slaves active was quite low. People used to complain that the power draw from their tv was high enough to not trigger the slaves to switch off.

      • c64 on 18/12/2019 - 09:52

        things to consider: the maximum load the board will switch and also the combined load going through the powerboard. if you've got a 1200W switched load then your saw needs to be less than 1200W or you might trigger the overload protection on the powerboard. for high loads, what you really want is a relay on one circuit that switches a load on a different circuit

  • reubot on 21/01/2020 - 22:27
    +1

    I have also found this one on eBay https://www.ebay.com.au/itm/5-Outlet-Auto-Standby-Killer-Pow…

Login or Join to leave a comment
Login Join