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--- electrical:triac [2024/04/05 18:44]
frater_secessus created
+++ electrical:triac [2024/04/05 23:42] (current)
frater_secessus [actual examples of use]
@@ Line 8: / Line 8: @@
 {{  https://www.harborfreight.com/media/catalog/product/cache/9fc4a8332f9638515cd199dd0f9238da/5/9/59386_W3.jpg?125}}
-  * some devices **can work on less power** than they naturally pull.  Examples:  resistance loads like coil hot plates, simple coffeemakers, some electric motors((brushed only, not brushless))
+  * some devices **can work on less power** than they naturally pull.  Examples:  resistance loads like coil hot plates, simple coffeemakers, normal electric motors((brushed only, not brushless))
-  * a TRIAC((TRIode for Alternating Current)) is a particular circuit component, but also refers to a controller device that uses that internal component to adjust the power a device consumes.  They are often sold as "router speed controls" or similar.
+  * a TRIAC((TRIode for Alternating Current)) is a particular circuit component used to do this magic.  They are often found in , but also refers to a controller device that uses that internal component to adjust the power a device consumes.  They are often sold as "router speed control" or similar ("speed control" hereafter.
-  * a TRIAC must not be used with brushed motors or anything with electronics in it.  Simple analog devices only.
+  * the load can typically be reduced to ~50% of its normal draw
-  * running the load at a low percentage (50% of normal) will cause less heat in the TRIAC than running it at a high percentage (90% of normal).((we might argue that if you can run it at 90% maybe just remove the TRIAC and run the load at 100% the normal way))
+  * running the load at a low percentage (50% of normal) will cause less heat in the speed control than running it at a high percentage (90% of normal).((we might argue that if you can run it at 90% maybe just remove the speed control and run the load at 100% the normal way))
@@ Line 32: / Line 32: @@
 ===== inverter types =====
-There is little clear information on the topic since running them off inverters is an extreme minority position, but it appears that TRIACS work best on PSW inverters.  They may run on MSW but seem unable to reduce power
+There is little clear information on the topic since running them off inverters is an extreme minority position, but it appears that speed controls work best on PSW inverters.  They may run on MSW but seem unable to reduce power less effectively (see below) and may run hotter.
+While resistive loads don't care about MSW vs PSW, motors will run hotter and "notchier" on MSW.  So you might want to run the latter off PSW whether or not a controller is used.
 ===== actual examples of use =====
+One helpful Amazon reviewer((no way to link directly to the review, sorry)) shared these results:
+>> I used it this morning to control the heater element on my coffee maker - the coffee maker element is rated at 1440 W at 120V, and a Kill-a-watt registers 1420 from it. If set to non-variable mode the kill-a-watt registered 1410. When switched to variable, the output was as follows: at the lowest setting it output 687 W, at the middle of L it output 710, at the top of L: 750, at mid-M 812, at low H 955, and at the max the Kill-a-watt showed 1374 W. My desire was to reduce the output of the coffee maker to slow the brewing and it worked perfectly for that. The unit heats up whether in variable or non-variable mode, in variable mode it does get hotter, but not excessively in my opinion. Your mileage will likely vary...
+The above reviewer was able to vary the power from 48% to 97% of the normal measured power by adjusting the controller's knob. Note that **at ~50% power it will take about 2x as long to brew the coffee**.  Maybe you want that, or maybe you are willing to put up with it to be able to squeak through at 710w instead of 1420w.
+One RVer noted he tried the controller with a grinder on both PSW and MSW:((https://community.goodsam.com/t5/technical-issues/ac-motor-speed-controller-on-a-msw-inverter/m-p/1390700/highlight/true#M105971))
+>> The grinder did not go as slow as it does on psw, but slow enough.
+He didn't give numbers on the difference.
+Note from secessus:
+>> when I ran a measured 928w hotplate at the lowest controller setting the power was ~550w, or about 60% of  normal full power.
+So until further information is forthcoming **we might ballpark speed controls on PSW reducing power to ~50% of normal and MSW to ~60% of normal**. But another Amazon reviewer((again, can't link)) says:
+>> ...there is a hidden adjustment potentiometer inside for minimum power setting. Wall dimmer switches have these as well. I was able to adjust it, but I’m waiting for my tachometer to get it where it needs to be. By the sound of the motor, I can tell it will go down enough. They really should disclose this adjustment in the instructions… Note: The hidden adjustment is soldered onto the top side of the PCB inside but you need to use a small flathead screwdriver to adjust it from the back after removing the back cover.
+See [[https://www.youtube.com/watch?v=-ilWK_VVEzc&t=710s|this video]] to see the pot adjusted. After adjustment secessus was able to hold 33% of rated power stably;  any further adjustment caused the circuit to drop out.
+===== sources =====
+Note that the Amp rating on these is at 120vac.  8A is 1000w, 9A is 1120w, 15A is 1800w.
+  * harbor freight sells [[https://www.harborfreight.com/router-variable-speed-control-dial-59386.html|an 8A version]]
+  * Amazon has [[https://amzn.to/3J5GkqD|many in different Amp ratings]]
+===== further reading =====
+  * [[https://circuitdigest.com/tutorial/triac-switching-circuit-and-applications|TRIAC switching circuit and applications]]
+  * YT:  [[https://www.youtube.com/watch?v=jS9ANqJf-ZY|TRIAC AC Dimmer Circuit - How to dim AC Power for Motors and More]], especially the oscilloscope section that starts [[https://youtu.be/jS9ANqJf-ZY?si=Hf2VZkyTCwSry9im&t=110|at 1:50]].

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