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# Question(s) about the Microchip dimmer

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#### Chris in Mesa

##### New Member
I hope someone can help me out. I'm attempting to build my first circuit (the incandescent dimmer circuit from the microchip site):

https://www.electro-tech-online.com/custompdfs/2009/09/91094A.pdf

I was putting together a parts list and when I came to the resistors, I didn't know the wattage that I needed - only the Ohms are listed. If anyone can help me figure out the wattage of the resistors, it would help a lot.

I searched the forums and came across another dimmer design. Does anyone with experience have an opinion as to whether one schematic is “better” than the other?

Does anyone know if I can just use a generic IR transmitter / receiver pair instead of the ones listed?

On the diagram of the receiver (see attached), there are several places (near the lower left for instance) where the lines are terminated with an arrow. Where does this connection "really" go? For example, the arrow to the left of the 47 mfd capacitor, and the arrow on the number "2" of the IR receiver [GP1UD261RK]. I’ll take an answer or a link, or an hint as to where to find that information out for myself.

One more question (for now). What do you think the jumpers are for?

So basically, I will take any help that the community can give. I have tried to do my homework before submitting.

Thanks a bunch! Chris

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#### mikeReynolds

##### Member
Chris, either circuit will work but be careful with the Microchip circuit. It is directly connected to the AC line and uses a resistor divider and zener to drop the voltage down to 5 volts. This method needs fewer parts but can be LETHAL if you are not careful. To answer your questions about the resistors, 1/8 watt should also work for the ones not marked with a wattage but if you have 1/4 watt they will also be fine. About the "arrows" that is the normal method of indicating circuit "ground" , connect all of the arrows that do not have +5V together and connect all of the arrows that have +5V beside them together. JP1 and JP2 are there to allow you to remove them and program the circuit using ICSP (In Circuit Serial Programming). J3 of course is your ICSP header, J2 would go to your light bulb, J1 goes to AC line (110 as most of us here in the States normally call it).

I do not quite follow you on the generic transmitter/receiver pair for the IR. The transmitter is made from scratch as shown in the 2nd picture you attached. Make sure you download the source code or hex file for it, I can't remember if it is in the zip file for 91094A or not. As for the receiver for best results use the one indicated, if substituting make sure you use one for a 38 kHz carrier

#### mikeReynolds

##### Member
About the "arrows" that is the normal method of indicating circuit "ground" , connect all of the arrows that do not have +5V together and connect all of the arrows that have +5V beside them together.

SHOULD HAVE BEEN

About the "arrows" that is the normal method of indicating circuit "ground" and "supply" , connect all of the arrows that do not have +5V together and connect all of the arrows that have +5V beside them together.

Mike

#### Chris in Mesa

##### New Member
Awesome

Mike, Thanks for the help! You did answer my question about the transmitter. I was referring to the actual IR transmitting/receiving Diodes.

At the local electronics shop (Frys Electronics) I found a pair of IR transmitting and receiving LEDs. My question was "could I substitute these instead?". It looks like as long as they are 38 kHz I might be good. The only place I found the exact part number was on Mouser Electronics and they were on backorder. I didn't want to pay $7.50 "backorder shipping" for a$1.25 part I did go ahead and order a 38kHz substitution pair from them anyway.

Thanks for the tip on D/L-ing the source code. I managed to hunt that down in the zip file on the Microchip site a couple of days ago.

You have been a big help, thanks for your time / knowledge!

#### mikeReynolds

##### Member
Chris,

Sorry for being so late getting back to you on this. The receiver is not just a diode, it is a complete receiver and demodulator circuit contained in a 3 pin package. You will not be able to substitute just a diode for it. On the bright side, you can likely pick-up a suitable substitute at a local Radio Shack if you are in a hurry to build the project or if you ordered a diode only instead of a receiver module

Mike

#### <NAME>

##### New Member
Ah....

Thanks. I didn't realize that the IR receiver contained a demodulator built in. You likely saved me some debugging time! Can I trouble you (or the community) with another question. I thought I could figure out the capacitor voltage, but had to guess when confronted with the myriad of available options at the store. From what I can tell, all capacitors on this schematic are at +5 volts because they are already being knocked down from 110V to 5V by passing thru the two resistors and the zener diode. Did I read the schematic correctly?

#### mikeReynolds

##### Member
Chris, sorry for being so long in getting back to you but my internet has been down due to a fried modem. The only one I would worry about is the 47 uf right after the zener. That one I would use at least a 50 volt cap

#### <NAME>

##### Active Member
Hi mike I have seen this circuit & never went to analize that.

Oops it is using ROC function to detect the ZX.Thats a nice idea.

Have you built this how was the smoothness in the brightness?

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#### <NAME>

##### New Member
Mike, No Sweat about taking time to get back and bummer about the modem. I ordered everything that I couldn't find at the local electronics shop. I was surprised at how small everything is. I haven't yet assembled the board (bread board) because I'm not sure how I can attach the components. I have only soldered a couple of times in my life (all within the last two weeks). So, I'm trying to either find "life size" replacement parts, or work on my soldering Warning - I may post some follow up questions here, lol. Thanks again! C.

#### mikeReynolds

##### Member
Hi mike I have seen this circuit & never went to analize that.

Oops it is using ROC function to detect the ZX.Thats a nice idea.

Have you built this how was the smoothness in the brightness?

Gayan,

I have not built this circuit so I can't personally comment on smoothness but it is divided into 8 steps basically increasing 12% in each step. I have however built a similar ckt using only 3 steps and from experience with that circuit would have to say that 8 steps would be much smoother.

Mike

#### kchriste

##### New Member
Forum Supporter
Whatever you do, don't connect the programmer when the circuit is powered by AC! A blown modem will not be the only dead piece of gear. Be careful!

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#### <NAME>

##### New Member
Some Good news..I have built both boards at got the remote to work. I haven't been able to get the dimmer board to work yet though. I'm going to rebuild it and try again. I do have one question before I start. In the docs (see here: https://www.electro-tech-online.com/custompdfs/2009/11/91094A.pdf) on page 3 it talks about adding a 330 mfd filter cap. as part of the transformerless power supply. I don't see that in the schematic though. Anyone know if this is an oversite, or is there something I don't know?

#### mikeReynolds

##### Member
Chris,

Replace the 47 ufd capacitor in the schematic with the 330 ufd. This could be why the circuit doesn't work, not enough power for the devices.

#### Chris in Mesa

##### New Member
Mike, thanks for the quick reply (again). I can't wait to get home and try this out!

#### Chris in Mesa

##### New Member
How do I figure out the average current of a triac burst?

Hopefully someone will have pity on my poor soul and clue me in! I have been trying for days to figure out what is glossed over in an application note for this dimmer circuit: Application Note 91094A from Microchip (the link is in the first post of this thread; I'm hesitant to add any external links since several of my last posts have never made it live.) Near the bottom right of page 2, it says:

Assume that the load is a 100 Watt light bulb with a
typical filament resistance of approximately 1Ω. The
triac should be conducting 5 mA when the AC line voltage
reaches 5V. Translating this into a conduction
angle, the 5 mA hold current should have been
reached 2 degrees following the zero crossing (see
Equation 1).
EQUATION 1:
Angle = invsin(5V/(110V * 1.414))

Assuming a 60 Hz system, the minimum 5 mA hold
current should be achieved after 93 microseconds of
bias current (see Equation 2).
EQUATION 2:
Time = (1/60 hz) * (2°/360°)

So, we only need to hold the bias current of 3 mA for
approximately 100 μS to latch the triac on. If we average
the narrow pulse of current over ½ of a 60 Hz
cycle, it gives us an average current requirement for
the triac bias of less than 37.5 μA.

My problem is with the last sentance. I have a different triac with different trigger / holding currents and I can't figure out how they arrived at an "average current requirement of 37.5μA". I have a MAC4DHM from On Semiconductors with a trigger current of 1.8 mA (typ) - 5.0 mA (max) and a holding current of 1.5 mA (typ) - 15 mA (max). Hmm... I just saw that I have been working off of the MAX values, not realizing it. Anyway, I would assume that since their values of 3/5mA used in the equation are within the range of my triac, that I could the same equation, but I need to be sure. Can anyone throw an equation my way that can explain how they arrived at 37.5 μA avg? P.S., I've read every datasheet/example on triacs that I could google, but no luck.

Thanks, Chris.

#### mneary

##### New Member
They are delivering a pulse for 100μs, once every 8.33ms. That's 1/83.3 duty cycle, or 1.2 percent. The pulse is 3mA, so the average power drawn is 3mA*0.012 or or 36μA.

This means that 36 (or 37.5) μA needs to be delivered to the storage capacitor so it can be recharged between pulses.

#### Chris in Mesa

##### New Member
Awesome! To be honest, it took me a minute to figure out where the 8.33 came from, but I got it: 1000(mS)/120(60hz*2) for each wave. Thanks again!

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June 1, 2009 nucl-ex
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Dec. 12, 2008 astro-ph
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Nov. 17, 2008 astro-ph
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• ### A Catalog of 24um Sources Toward the Galactic Center(0811.1557)

Nov. 10, 2008 astro-ph
We present a 1.5deg x 8deg (220pc x 1195pc) Multiband Imaging Photometer for Spitzer 24um image of the Galactic Center and an accompanying point source list. This image is the highest spatial resolution (6" ~ 0.25pc) and sensitivity map ever taken across the GC at this wavelength, showing the emission by warm dust in unprecedented detail. Over 120,000 point sources are identified in this catalog with signal-to-noise ratios greater than five and flux densities from 0.6mJy to 9Jy.
• ### Mass measurements in the vicinity of the rp-process and the nu p-process paths with JYFLTRAP and SHIPTRAP(0808.4065)

Aug. 29, 2008 nucl-ex
The masses of very neutron-deficient nuclides close to the astrophysical rp- and nu p-process paths have been determined with the Penning trap facilities JYFLTRAP at JYFL/Jyv\"askyl\"a and SHIPTRAP at GSI/Darmstadt. Isotopes from yttrium (Z = 39) to palladium (Z = 46) have been produced in heavy-ion fusion-evaporation reactions. In total 21 nuclides were studied and almost half of the mass values were experimentally determined for the first time: 88Tc, 90-92Ru, 92-94Rh, and 94,95Pd. For the 95Pdm, (21/2^+) high-spin state, a first direct mass determination was performed. Relative mass uncertainties of typically $\delta m / m = 5 \times 10^{-8}$ were obtained. The impact of the new mass values has been studied in nu p-process nucleosynthesis calculations. The resulting reaction flow and the final abundances are compared to those obtained with the data of the Atomic Mass Evaluation 2003.
• ### TRIGA-SPEC: A setup for mass spectrometry and laser spectroscopy at the research reactor TRIGA Mainz(0805.4475)

May 29, 2008 nucl-ex
The research reactor TRIGA Mainz is an ideal facility to provide neutron-rich nuclides with production rates sufficiently large for mass spectrometric and laser spectroscopic studies. Within the TRIGA-SPEC project, a Penning trap as well as a beam line for collinear laser spectroscopy are being installed. Several new developments will ensure high sensitivity of the trap setup enabling mass measurements even on a single ion. Besides neutron-rich fission products produced in the reactor, also heavy nuclides such as 235-U or 252-Cf can be investigated for the first time with an off-line ion source. The data provided by the mass measurements will be of interest for astrophysical calculations on the rapid neutron-capture process as well as for tests of mass models in the heavy-mass region. The laser spectroscopic measurements will yield model-independent information on nuclear ground-state properties such as nuclear moments and charge radii of neutron-rich nuclei of refractory elements far from stability. This publication describes the experimental setup as well as its present status.
• ### SPITZER SAGE Observations of Large Magellanic Cloud Planetary Nebulae(0710.5938)

Nov. 1, 2007 astro-ph
We present IRAC and MIPS images and photometry of a sample of previously known planetary nebulae (PNe) from the SAGE survey of the Large Magellanic Cloud (LMC) performed with the Spitzer Space Telescope. Of the 233 known PNe in the survey field, 185 objects were detected in at least two of the IRAC bands, and 161 detected in the MIPS 24 micron images. Color-color and color-magnitude diagrams are presented using several combinations of IRAC, MIPS, and 2MASS magnitudes. The location of an individual PN in the color-color diagrams is seen to depend on the relative contributions of the spectral components which include molecular hydrogen, polycyclic aromatic hydrocarbons (PAHs), infrared forbidden line emission from the ionized gas, warm dust continuum, and emission directly from the central star. The sample of LMC PNe is compared to a number of Galactic PNe and found to not significantly differ in their position in color-color space. We also explore the potential value of IR PNe luminosity functions (LFs) in the LMC. IRAC LFs appear to follow the same functional form as the well-established [O III] LFs although there are several PNe with observed IR magnitudes brighter than the cut-offs in these LFs.
• ### Direct mass measurements beyond the proton drip-line(nucl-ex/0701030)

Jan. 22, 2007 nucl-ex
First on-line mass measurements were performed at the SHIPTRAP Penning trap mass spectrometer. The masses of 18 neutron-deficient isotopes in the terbium-to-thulium region produced in fusion-evaporation reactions were determined with relative uncertainties of about $7\cdot 10^{-8}$, nine of them for the first time. Four nuclides ($^{144, 145}$Ho and $^{147, 148}$Tm) were found to be proton-unbound. The implication of the results on the location of the proton drip-line is discussed by analyzing the one-proton separation energies.

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# Configuration¶

When using SDF3 inside Spoofax, several configuration options are relevant. They allow using the new parser generator, specifying the shape of completion placeholders, or disable SDF altogether. These options should be specified in the metaborg.yaml file.

For example, to disable SDF for the current project, use:

language:
sdf:
enabled: false

SDF3 allows generating placeholders for code completion. The default "shape" of placeholders is $Symbol. However, it is possible to tweak this shape using the configuration below (the configuration for suffix is optional): language: sdf: placeholder: prefix: "$"
suffix: "\$"

Currently, the path to the parse table is specified in the Syntax.esv file, commonly as table: target/metaborg/sdf.tbl. When the ESV file does not contain this entry, it is also possible to specify the path to the parse table in the metaborg.yaml file. This is useful when testing an external parse table, or using a parse table different from the one being generated in the project. In the example below, the table is loaded from the path tables/sdf.tbl. The same can be applied to the parse table used for code completion.

language:
sdf:
parse-table: "tables/sdf.tbl"
completion-parse-table: "tables/sdf-completions.tbl"

In a Spoofax project, it is also possible to use SDF2 instead of SDF3. This enables SDF2 tools such as the SDF2 parenthesizer, signature generator, etc. For example:

language:
sdf:
version: sdf2

By default SDF3 compilation works by generating SDF2 files, and depending on the SDF2 toolchain. However, a new (and experimental) parse table generator can be selected by writing:

language:
sdf:
sdf2table: java

This configuration disables the SDF2 generation, and may cause problems when defining grammars to use concrete syntax, since this feature is not supported yet by SDF3. However, the java parse table generator supports Unicode, whereas SDF2 generation does not. Furthermore, dynamic can be used instead of java, to enable lazy parse table generation, where the parse table is generated while the program is parsed.

A namespaced grammar can be generated automatically from an SDF3 grammar. This namespacing is done by adding the language name to all module names and sort names. The generated grammar is put in src-gen/syntax.

The configuration to enable this is:

language:
sdf:
generate-namespaced: true

Note that namespacing doesn't not handle imports of grammar files from other projects very well.

## JSGLR version¶

An experimental new version of the SGLR parser implementation is available: JSGLR2. It supports parsing, imploding and syntax highlighting.

Error reporting, recovery and completions are currently not supported. It can be enabled with:

   language:
sdf:
jsglr-version: v2

There are some extensions of JSGLR2 available. To use them, change the jsglr-version by replacing v2 with one of the following:

• data-dependent: Data-dependent JSGLR2 solves deep priority conflicts using data-dependent parsing, which does not require duplicating the grammar productions.
• incremental: Incremental JSGLR2 reuses previous parse results to speed up parsing.
• layout-sensitive: Layout-sensitive JSGLR2, see Layout Sensitivity.
• recovery: JSGLR2 with recovery tries to recover from parse errors. This extension is experimental.
• recovery-incremental: Incremental JSGLR2 with recovery. This extension is experimental.

## JSGLR2 logging¶

Logging is available for JSGLR2. It can be enabled with:

language:
sdf:
jsglr2-logging: all

Since logging all parsing events is quite verbose, several other scopes are available in addition to the all option:

• none: Log nothing (default).
• minimal: Only log the start and end of a parse, including a measurement of total parse time (including imploding and tokenization).
• parsing: Log all standard parsing events (such as stack and parse forest operations, action execution, etc.) but no variant-specific events (e.g. related to recovery).
• recovery: Log the recovery iterations and the recovery productions that are applied.

Last update: 2022-05-27


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anonymous 4 years ago What is the limit of 8x^4-3/2x+5x^4 when x is approaching infinity?

$\frac{8}{5}$ since the degrees are the same it is the ratio of the leading coefficients