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ArcticMyst Security by Avery

Searching for switching IC

Joined
May 7, 2016
Messages
139
Points
28
hello, i'm searching for an IC similar to an 555 timer. But all in one. I need a pulse generator with an frequency of 2Hz and a duration of 200ms or lower. Is there an IC for this? Or anything near that range?


Edit!!!!!
A hall effect sensor is also alright!, but i need a hall effect sensor (or a similar toggle switch) like a magnetic sensor, whenever i put a magnet close to it, it should make a continuity of positive voltage on the output, but whenever i remove the magnet (regardless of which pole, North or South), it should turn off., can someone help me finding this one? Package must be small, as small as a 8 pin dip IC or smaller, it would be amazing if i don't need any external components.


So all in short,

An IC that bridges or pulses voltage + every second with a duration of 200ms or less

Or a hall effect sensor that turns on when magnet is applied, but turns of when magnet is removed, REGARDLESS of which pole.

Any info or link to the IC's datasheet would be awesome :D

By the way, are there IC's that let current trough when tapped or shocked against something? (Momentary current) not continues as this bypasses my laser security measure.



All of this is needed for a security measure inside a laser pen
 
Last edited:





Benm

0
Joined
Aug 16, 2007
Messages
7,896
Points
113
You could use a hall effect sensor and a microcontroller to interpret its output - using smt components that would fit the envelope of a socketed DIP-8 package easily.

Similarly you could (also) add an accelerometer sensor to the microcontroller to check for any sudden movements like taps (similar to how a smartphone does that).

All of these things are available in VERY small packages as they are commonly used in smartphones and such. One challenge would be finding ones that you can actually hand solder, stuff like BGA isn't that easy to use, unless you can print good solder masks and have a reflow oven handy. 
 
Joined
May 7, 2016
Messages
139
Points
28
You could use a hall effect sensor and a microcontroller to interpret its output - using smt components that would fit the envelope of a socketed DIP-8 package easily.

Similarly you could (also) add an accelerometer sensor to the microcontroller to check for any sudden movements like taps (similar to how a smartphone does that).

All of these things are available in VERY small packages as they are commonly used in smartphones and such. One challenge would be finding ones that you can actually hand solder, stuff like BGA isn't that easy to use, unless you can print good solder masks and have a reflow oven handy. 

Hello, thanks for your answer, i have a good amount of iPod and iPhone circuit boards laying around. I got 2 loose accelerometers (bga) but those are pretty easy to solder on. I didn't tought about that. But i didn't find any IC related to them except for the motion controller but that thing is glued and nano-soldered in place. Do you know any IC's which i can use for that? The accelerometer is small, if i can get the same package as this, it would fit. All it needs to do is give a brief positive voltage pulse.

And do you know a circuit for a 555 timer IC, i need to get 1Hz and a brief pulse, with brief, i mean 200ms or something close. I can't figure it put. Luckily, i found some ultra small 555's, even smaller then dip-8, can i use surface mount resistors and ceramic surface mount capacitors for setting this up

The ic is an LMC555CMM, as this thing can operate at ultra low voltages, almost no current draw and very small.

I doubt the micro controller and accelerometer would fit in there, as my hosts is very small, this 555 could easily fit in there if i'm correct.

However thanks for the reply:D
 
Last edited:

Benm

0
Joined
Aug 16, 2007
Messages
7,896
Points
113
There are examples in the 555 datasheet to get variable duty cycles and frequencies - working out 1 Hz with 20% should not be a problem, though you may need fairly large capacitors do get that slow.

As far as space goes i don't think you can do much to beat a uC here as it can perform multiple functions: At can interpret the accelerometer, hall sensor and also function as the switchmode regulator chip all at once, perhaps with an external transistor for the latter depending on power requirement.

You can use something like a attiny85 that comes in packages from dip-8 all the way down to QFN if you are willing/able to solder that small.

And yes, you can do the switching power supply with a microcontroller that has analog inputs, albeit at somewhat limited switching frequency. Depending on the power required a dedicated chip might work better since it can switch faster resulting in smaller caps and inductors to some degree.
 





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