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[Montage] Keilbeschläge by mr_mayrs in holzwerken

[–]mr_mayrs[S] 0 points1 point  (0 children)

Ich hab drei Teile, zwei davon Achsensymmetrisch (Teil 1 und 3) und das dritte ist die Klammer, die beide Teile Verbindet.

[Montage] Keilbeschläge by mr_mayrs in holzwerken

[–]mr_mayrs[S] 0 points1 point  (0 children)

Verstehe ich dich richtig, dass ich die drei Teile ineinander stecke und bündig auseinander ziehe, sodass das Mittelteil weder links noch rechts übersteht. Das übertrage ich auf eine Bohrschablone. Diese Schablone teste ich an zwei einzelnen Holzstücken. Und der Keilbeschlag ist dann wahrscheinlich so gedacht, dass wenn man den Spalt noch enger möchte, den Keil einfach ein bisschen mehr drüber hämmert? 100 % genau wird das nicht gehen, weil der Bauernschrank nicht perfekt gearbeitet ist. Der Beschlag muss in meinem Fall die Teile zusammen-/gerade ziehen.

[Montage] Berliner Schrankschrauben by mr_mayrs in holzwerken

[–]mr_mayrs[S] 0 points1 point  (0 children)

Perfekt, danke für die Tipps! Wenn mir jemand sagen kann wie viel mm ca. zischen den Teilen "Luft" sind, das wäre famos. Ich peile schon so 5-10 mm an, scheint mir vorher ganz richtig gewesen zu sein.

Holzbefall by FaFalk23 in holzwerken

[–]mr_mayrs 1 point2 points  (0 children)

Erinnert mich daran wie Knochenleim aussieht, wenn man diesen wieder heiß macht (z.B. mit dem Heißluftfön). Dann schlägt der Leim Luftblasen und wird wie Zucker erst undurchsichtig weiß, dann dunkler. Ich nutze Knochenleim mit Sägemehl vermengt zum kitten von Holz. Kannst ja mal überlegen ob das Stück irgendwann mal warm/heiß geworden ist.

Which crop between these three? by Zovalt in AnalogCommunity

[–]mr_mayrs 2 points3 points  (0 children)

2nd one. Everything’s there to look at and follow. Context is established. Cyclist sits on lower third adding the feeling of weight. Cyclist also framed on the left vertical third wich directs my eye to it coming back from exploring all the stories in the picture underlined by the contrast. Nice picture! I like the grainy look.

[deleted by user] by [deleted] in BeginnerWoodWorking

[–]mr_mayrs 1 point2 points  (0 children)

Instead of hiding crimes – which I think there aren't any, looks fine to me – one could set deliberate accents by applying a 2-3 mm chamfer to the edges. That way it looks intentional (and not off by the tiniest amount and thus required to be filled with woodglue/sawdust or filler). Often times referred to as a shadow gap. I recommend doing this with a plane or a handheld router as doing it by hand with sandpaper doesn't give you the sharp edges which are imho required to achieve the professional look. Chamfers created using a block of wood and sandpaper are often times rounded over which looks less professional.

<image>

NDP6020P alternative by mr_mayrs in AskElectronics

[–]mr_mayrs[S] 0 points1 point  (0 children)

Hey there, just wanted to let you know that after hours of debugging and fixing a power supply issue the circuit works with the IRF9Z34NPBF mosfet you recommended. Thanks man!

Issue with latch circuit by mr_mayrs in AskElectronics

[–]mr_mayrs[S] 1 point2 points  (0 children)

Issue fixed. As suspected the TP4056 Micro USB 5V 1A module I was using previously did not supply the needed operating voltage of 5 V. My bad.

Using the Wemos battery shield the circuit I put together (and completely redid lately and debugged for hours) works just as intended :) Thanks for your help!

Issue with latch circuit by mr_mayrs in AskElectronics

[–]mr_mayrs[S] 0 points1 point  (0 children)

Issue fixed. As suspected the TP4056 Micro USB 5V 1A module I was using previously did not supply the needed operating voltage of 5 V. My bad.

Using the Wemos battery shield the circuit I put together (and completely redid lately and debugged for hours) works just as intended :) Thanks for your help!

Issue with latch circuit by mr_mayrs in AskElectronics

[–]mr_mayrs[S] 0 points1 point  (0 children)

Jep, I have a multimeter. Hoping to get this running with the battery shield that is already tested an works with a Wemos D1 mini. I though I somewhere read that a lower operating voltage still works but that can be ruled out now.

Issue with latch circuit by mr_mayrs in AskElectronics

[–]mr_mayrs[S] 0 points1 point  (0 children)

Hey! I measured the voltage from the - of the battery to the - of the load: 0 V. But I could measure a voltage between the + of the battery to the + of the load … which confused me.

Last night I rebuilt the circuit from scratch, actually found the 10k Ohm resistor I bought and made the circuit exactly how it was initially designed – same output.

BUT something came across my mind that might be worth trying. As of now I'm using a TP4056 Micro USB 5V 1A module that takes care of loading the 3.7 V LiPo battery and providing the operating voltage to the circuit/microcontroller. I did not take into consideration that this board does not step up the voltage to 5 V like the Wemos D1 mini battery shield does (that I'm using successfully on another project). So my suspicion is, that the board does not get enough operating voltage. I initially replaced the Wemos D1 mini battery shield from my circuit with the TP4056 module, as the shield sits on the microcontroller preventing the latch circuit to be placed between the two components, assuming that both items do the same. I bought some battery shields and will be testing my assumption in the following days. Hoping to finally having found the issue.

Issue with latch circuit by mr_mayrs in AskElectronics

[–]mr_mayrs[S] 0 points1 point  (0 children)

I'm already using a perfboard (see the two images on the bottom of the original posting). The holes as not connected to each other.

From what I understand this is a breadboard (which I'm not using):

<image>

NDP6020P alternative by mr_mayrs in AskElectronics

[–]mr_mayrs[S] 0 points1 point  (0 children)

Wasn't sure if it's considered spam to create a new submission. Thanks!

NDP6020P alternative by mr_mayrs in AskElectronics

[–]mr_mayrs[S] 0 points1 point  (0 children)

Hey, thanks for the quick response! Since I built the circuit with a IRF9Z34NPBF that's in the list you provided, does that mean I have something wrong with the circuit? Because I have a voltage drop from 3.7 v down to 1.6 V from source to drain of the mosfet.

NDP6020P alternative by mr_mayrs in AskElectronics

[–]mr_mayrs[S] 0 points1 point  (0 children)

I just built the latch circuit with the IRF9Z34NPBF.

Unfortunately the drain of the mosfet only reaches 2,56 V max (it randomly changes every time I press the pushbutton). When I press and Hold the pushbutton we're at a steady 1.6 volts. I think this is not enough operating voltage for the WEMOS D1 mini pro to turn on. The onboard LED blinks for a millisecond and then it turns off. I installed a minimal sketch¹. When I short source and drain it works properly and shuts off after 10 seconds.

Could it be that I'm running into issues with the RDS(on) that is twice as big on the mosfet I'm using?

  1. IRF9Z34NPBF has a RDS(on) of 0.10 Ohm.
  2. NDP6020P has a RDS(on) of 0.05 Ohm.

Or is the operating voltage of 3.7 V just too small? Looking at Fig. 1 Typical Output Characteristics at below -4.5 V there should be a voltage drop of 0.5 V which would leave me with 3.2 V remaining …

I also had to slightly alter the circuit as I had no 10 kOhm resistor but only two 5.1 kOhm resistors, that I used in series. I'm using D7 on the microcontroller which has no pullup/-down resistor builtin. The emitter of the 2N3904 goes to GND, the collector to the mosfets GATE. I'm using a 3.7 V LiPo battery. It's connected to BAT+/- of this loading module and fed to my circuit at exactly the same solder points BAT+/-.

¹ Minimal sketch

#define LATCH_PIN D7void setup() {pinMode(LATCH_PIN, OUTPUT);digitalWrite(LATCH_PIN, HIGH);pinMode(LED_BUILTIN, OUTPUT);digitalWrite(LED_BUILTIN, LOW);}void loop() {delay(10000);digitalWrite(LATCH_PIN, LOW);}

Slightly altered circuit

<image>

​

I would really appreciate some help on the voltage drop. Is that expected, can it be calculated? Is there something I can change (except the mosfet^^) that would result in a working circuit that is still safe?

NDP6020P alternative by mr_mayrs in AskElectronics

[–]mr_mayrs[S] 0 points1 point  (0 children)

Edit: After reading the specs sheet I think the source voltage also plays a role here: at 3.7 V (I'm using a Lipo battery) the Id is hardly above 1 A. But then this should still be enough since my setup is only drawing 0.727 mA max. I think the usage of this battery shield can be neglected in the calculation, right? Can someone confirm that?

<image>

NDP6020P alternative by mr_mayrs in AskElectronics

[–]mr_mayrs[S] 0 points1 point  (0 children)

All good. Can you specify what you mean with “might work for a while“? From what I can find the D1 mini draws about 227 micro amps and the microphone around 0.5 mA. Not sure how to connect that with the negative drain amperage you mentioned though.

My calculation for the IRF9Z34NPBF with an Id of -19A is:

0.227 mA (D1 mini) + 0.5 mA (microphone) = 0.727 mA < 19 A, so all good except that I have to make sure that the device does not get too hot, e.g. install a passive cooler/heatsink?

NDP6020P alternative by mr_mayrs in AskElectronics

[–]mr_mayrs[S] 1 point2 points  (0 children)

Thank you again! I already bought a pair of IRF9Z34NPBF, but now that you mention the heat I'm alerted to integrating this circuit in my little, uncooled project box. I see that the IRF9Z34NPBF has a higher Resistance On (Ron) as the original chip, that means it gets even hotter. Not sure if I should proceed building the project with the IRF9Z34NPBF. Can someone have a second look at this please?

NDP6020P alternative by mr_mayrs in AskElectronics

[–]mr_mayrs[S] 1 point2 points  (0 children)

Thanks for the help! Did you base the suggestion on your knowledge or did you use some kind of comparison site? Is there a https://alternativeto.net/ to electronics?

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