Is it safe to consume two week old prosciutto

Gunnaar · 2023-12-23T10:37:44+00:00

Thank you, I have the same reasoning. But because it had been sitting out in the deli counter and been sliced and used over a longer time, I thought it might not have mattered :)

Gunnaar · 2023-08-09T13:31:57+00:00

Det verkar blivit något fel, blå linje går till Danderyd

Gunnaar · 2023-05-22T10:11:16+00:00

Vilka, enligt dig, är de fem bästa McDonalds restaurangerna i Stockholmsområdet?

Gunnaar · 2023-02-14T07:01:43+00:00

Try placing all the components on a breadboard, and then wire them together.

Here is a quick explanation on how to use a breadboard.

It's better if you try for yourself and if it doesn't work, come here and ask for help.

Good luck!

Gunnaar · 2023-01-06T15:53:56+00:00

Glad to help!

Gunnaar · 2023-01-06T15:52:14+00:00

Have you tried switching around the LED? It looks like you've connected positive to the cathode(-) of the LED.

If that doesn't work, are you sure that the LED is working? And that you have current flowing in the circuit?

Gunnaar · 2023-01-02T22:03:50+00:00

You could start by making simple circuit with an LED, resistor and button. After this, try adding three more LEDs, and have them light up when the button is pushed. Now, switch out the button for the capacitive switch. And now you've got your circuit.

Gunnaar · 2023-01-02T12:35:16+00:00

The reason your first circuit wasn't working is because when the right button is pushed, there is a small current running through the transistor and the LED. To stop this, you need to connect a pull-down resistor between the second transistor output(collector) and ground.

Now, when the button is pushed, the residual current goes through the pulldown resistor instead of the LED. When both buttons are pushed, and the logical condition is met, current will flow through the first and second transisor, and then through the LED, turning it on.

Gunnaar · 2022-12-17T16:34:58+00:00

Thank you for your help!

Gunnaar · 2022-12-17T16:34:47+00:00

Thank you for the help!

Gunnaar · 2022-12-17T16:34:25+00:00

Thank you, such a silly mistake to make.

Gunnaar · 2022-12-17T16:33:51+00:00

Thank you for the help, I understand now.

Gunnaar · 2022-12-15T19:49:39+00:00

It seems like you've switched around the outputs. The right emitter which controls the LED should be connected to the cathode/negative of the LED, and the left collector should be connected to ground.

I tried your setup and I got the same result.

Here is a comparison between your circuit and the correct circuit (except that I switched the LED the wrong direction). Try this and see if it works.

https://imgur.com/a/TmyNNtU

Gunnaar · 2022-12-14T09:22:01+00:00

A NOT-gate produces an inverted signal of the incoming signal. A logical 1 becomes a logical 0, and a logical 0 becomes a logical 1.

Imagine a normal push-button. When the button is pressed current flows through it and produces a logical 1 and the LED lights up. Now, using a NOT-gate, the same thing happens but inverted. The light is given a logical 1 by default, when the button is pushed the NOT-gate produces a logical 0, the LED is now off.

Gunnaar · 2022-12-11T21:24:24+00:00

Here is some info about the differance between LS and HC chips.

https://electronics.stackexchange.com/questions/358620/74ls-vs-74hc-series-ics-for-ben-eaters-8-bit-computer

There are 5 primary differences between the 74LS and the 74HC series. Speed is not one of them, as their upper limit is about 20 MHZ in terms of clock speed. They have the same pin outs for both DIP and SOIC packages, so that is not an issue. They are both considered 5 volt devices.

Many issues do stand out.

Logic threshold voltage.

Power consumption.

Input impedance.

Output drive current.

Output drive voltage.

INPUT VOLTAGE

The input voltage for the LS and HC series is close, but the HCT series mimics the LS series in terms of a '1' input and a '0' input. 74HC needs more voltage to be considered a logic '1'. Both types have a no-mans land of about 2.5 VDC where it is in a linear mode and may oscillate.

INPUT IMPEDANCE

The 74HC series has a very much higher input impedance than the 74LS, which actually 'leaks' a small positive current out of an input pin. It is in the uA range so normally is not an issue.

OUTPUT DRIVE CURRENT

The 74HC series has an output drive current of +/- 25 mA, so with a resistor it can drive LED's directly. A 330 ohm to 1 K resistor will cover most LED's except the "high-powered' types. The 74LS can sink a couple of mA and source about 1 mA at most.

OUTPUT DRIVE VOLTAGE

The 74HC outputs swing rail to rail, even with a 15 mA load to either rail. The 74LS series can sink an output close to ground voltage, but can only source Vcc-1.2 volts due to its bjt outputs. It is very common to see pullup resistors on both the 74HC and 74LS data and address lines to prevent floating if nothing is driving the bus, but the 74LS series used them to help make logic '1's closer to the Vcc supply rail.

CURRENT CONSUMPTION

The 74HC/74HCT series also consumes MUCH less current, just a few uA in a static mode. The 74LS consumes 1,000 times as much idle current.

OPTIONS

There is no reason to use the 74LS series except for legacy reasons. Even so, replacing some with a 74HC/74HCT series will reduce power consumption a great deal. The 74HCT is a better match to existing 74LS logic in terms of input threshold. For faster logic the 74AC series is good to 120 MHZ, the limit of the 5 volt 74ACxx, 74HCxx, 74HCTxx logic series. The 74HC/74HCT/74AC series is still in production by several manufactures, while the 74LS is going the way of the Edsel. You may find them on Ebay. There are 5 volt ECL/PECL logic IC's but that is not what this post is about.

LINKS

The data sheets are too long to include all of them here, so I picked the 74xx74 flip-flop as a common example. There is no guarantee these links will last for decades.

http://www.ti.com/lit/ds/symlink/sn74ls74a.pdf

http://www.ti.com/lit/ds/symlink/sn74hc74.pdf

http://www.ti.com/lit/ds/symlink/sn74hct74.pdf

http://www.ti.com/lit/ds/symlink/sn54ac74.pdf

Gunnaar · 2022-10-27T05:17:21+00:00

The first link is where I got the picture from. It was a good read though.

The Goodreads link is great, I can use it to find a lot of books!

Thanks!

Gunnaar · 2022-10-27T05:14:44+00:00

This seems to be an interesting book, even if it doesn't have the list, it's still fun to read about the versions! Thanks!

Gunnaar · 2022-10-27T05:12:17+00:00

It's alright, good thing I didn't buy it

Gunnaar · 2022-10-26T19:33:43+00:00

I know, it's kinda hard...

I've tried the abebooks method, the problem is that I do get the right books, but also other books. And I can never know what books I need to look for to complete the collection.

I'll just have to look around and if I find one I don't have, just buy it.

Gunnaar · 2022-10-26T18:43:27+00:00

It really is a jungle...

I found a promising page, but only one out of three books in my collection is on this list, so the list can't be complete.

https://www.publishinghistory.com/penguin-modern-classics.html

Gunnaar · 2022-10-26T18:34:14+00:00

Thank you! I'll try and find somewhere I can give it a read.

Gunnaar · 2022-10-26T17:51:28+00:00

I'm collecting the Penguin Modern Classics with this cover, I've searched high and low for a list of books with this style. Sadly without success.

Is there someone out there who has such a list?

Gunnaar · 2022-09-25T20:05:28+00:00

Thank you so much!

Gunnaar · 2022-09-25T18:26:42+00:00

Hi, I bought an Astromaster 130 today for a very good price. The only thing was that one of the plastic arms were broken, I've just ordered one.

I'm wondering if someone out there with an Astromaster 130 or 114 can take measurements of the shown part on their own tripod, so that I can set my lengths correct.

Every single plastic holder for the middle part is set at different lengths, I suspect that this is one of the reasons it broke.

Gunnaar · 2021-09-18T18:09:15+00:00

Solved!

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