Required alternative of ic

Thread Starter

Berzin

Joined Dec 17, 2020
59
Hi guy
Actually I am doing a project with ic Ne 555 timer and Ic 4013 B flip flop. Where the 555 timer ic is the main one which starts and stops and the 4013 flip flop turns on the ic 555 on and off but i have a small problem that the machine which it is going to power requires negative pulse as it's positive pulse is coming from the other current where ic 555 (2) is working
In short two currents powering one machine where both current are handle by ic 555(1) and ic 555 (2). So ic 555 (2) is positive and ic 555 (1) is positive which I want to convert to negative ( without negative power my machine will not work)
I was advice by my friend to use LTC 3863 but it's not so available in India so can anyone suggest alternative to this Ltc 3863 which is easy available and user friendly
 

dl324

Joined Mar 30, 2015
13,143
A schematic would be helpful.

If I understand you correctly, you need the output of the 555 timer to be inverted. What is the output driving?
 

Irving

Joined Jan 30, 2016
2,111
Can you post the schematic of your project - its much easier to advise when we can see what you're trying to achieve.

Also this negative pulse. How wide, how negative, rise and fall times, etc?
Is this a control signal or actually a negative power line?
 
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Papabravo

Joined Feb 24, 2006
16,835
Hi guy
Actually I am doing a project with ic Ne 555 timer and Ic 4013 B flip flop. Where the 555 timer ic is the main one which starts and stops and the 4013 flip flop turns on the ic 555 on and off but i have a small problem that the machine which it is going to power requires negative pulse as it's positive pulse is coming from the other current where ic 555 (2) is working
In short two currents powering one machine where both current are handle by ic 555(1) and ic 555 (2). So ic 555 (2) is positive and ic 555 (1) is positive which I want to convert to negative ( without negative power my machine will not work)
I was advice by my friend to use LTC 3863 but it's not so available in India so can anyone suggest alternative to this Ltc 3863 which is easy available and user friendly
Most LT parts were, and likely still are proprietary. This means the likelihood of finding anything close with greater availability is exceedingly remote. It should not be hard to to design an inverting level shifter. Why not give us the complete schematic, show us where the problem is. I know at least 3 people here besides myself who could give you a fix. Unless of course your design is proprietary and you can't reveal the details.

BTW -- I don't sign NDAs
 

Thread Starter

Berzin

Joined Dec 17, 2020
59
As you all have required I have posted my systematic diagram which is incomplete as I want a ic which converts positive current to negative and using Ltc 3863 is out of question as I can't find it anywhere
This machine can't get direct ground as you all see it's getting current from two different ways
Ic 555 (2) will start first and then ic 555 ((1) will start
 

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Irving

Joined Jan 30, 2016
2,111
The TL7660/LMC7660 is available from several manufacturers and is easy to use, but has relatively low output current capability of less than 20mA. Its main purpose it to provide a -ve rail for dual-supply op-amps, A2D converters etc. Also, because of the switched capacitor approach, it doesn't cope well with switched rather than constant loads, the voltage regulation will suffer.

However its not clear from the schematic whether this is a control 'pulse' or a relay-controlled power supply. What voltage and current requirements does the 'machine' have? There will be better solutions.
 

Thread Starter

Berzin

Joined Dec 17, 2020
59
The TL7660/LMC7660 is available from several manufacturers and is easy to use, but has relatively low output current capability of less than 20mA. Its main purpose it to provide a -ve rail for dual-supply op-amps, A2D converters etc. Also, because of the switched capacitor approach, it doesn't cope well with switched rather than constant loads, the voltage regulation will suffer.

However its not clear from the schematic whether this is a control 'pulse' or a relay-controlled power supply. What voltage and current requirements does the 'machine' have? There will be better solutions.
9 volts min and 12 to 15 volts max 1 amp is required
 

Irving

Joined Jan 30, 2016
2,111
Oh, right the 7660 isn't going to work.

You need a fully assembled AC/DC power supply, or an isolated DC-DC converter from the +12v rail.

Where does your +12v come from?
 

Thread Starter

Berzin

Joined Dec 17, 2020
59
Oh, right the 7660 isn't going to work.

You need a fully assembled AC/DC power supply, or an isolated DC-DC converter from the +12v rail.

Where does your +12v come from?
Battery 12 volt 7200 mah
 
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Irving

Joined Jan 30, 2016
2,111
So you need an isolated DC-DC converter to get the -ve supply from +12v. Something like the TRACO TEL12-1212, available from Mouser.in or Digikey.in

Wired as:
+12v INpin 16
Ground INPin 1
Ground OUTPin 9
-12v OUTPin 10
 

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LesJones

Joined Jan 8, 2017
3,498
Your description is not very clear. Are the two signals from the NE555s in your circuit powering the machine or just sending control signals to it ? Does the machine require one power supply for example 0 volts and + 12 volts, 0 volts and -12 volts or 0 volts , +12 volts AND -12 volts. I am wondering if it is possible if it is possible to solve the problem by changing the power wiring to the machine. Full details of this "machine" would be a great help. (The full specifications of "the machine".
I am also wondering id just inverting the signal to one relay or using an NC contact on the relay instead of a NO would solve the problem.


Les.
 
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Irving

Joined Jan 30, 2016
2,111
Your description is not very clear. Are the two signals from the NE555s in your circuit powering the machine or just sending control signals to it ? Does the machine require one power supply for example 0 volts and + 12 volts, 0 volts and -12 volts or 0 volts , +12 volts AND -12 volts. I am wondering if it is possible if it is possible to solve the problem by changing the power wiring to the machine. Full details of this "machine" would be a great help. (The full specifications of "the machine".

Les.
Its not clear, is it. From the diagram and the power requirements it looks/sounds like the 'machine' needs sequenced power supplies, +12 before -12 but the lack of information hides many nuances.

More info regarding the 'machine' would be useful...
 

LesJones

Joined Jan 8, 2017
3,498
A FULL schematic showing the power rails (Including which one is being considered the common rail.) would be a great help. Also the connections to the relay contacts being shown in full. One relay does not show any connection to it's contacts and the other only shows one contact connection.

Les.
 

Irving

Joined Jan 30, 2016
2,111
You just need an negative output converter.
I see no reason for it to be isolated.

What manufacturer's parts can you get?
You're right of course, but for 1A output there are relatively few non-isolated inverting buck-boost converters and doing this from chip up needs careful PCB layout etc so given the likely capabilities of the TS based on the info so far I see that as a probable step too far...
 

wayneh

Joined Sep 9, 2010
17,153
I'm still confused about the goal. Sounds to me like you need an H-bridge, a standard circuit for reversing the polarity, for instance to a DC motor to reverse direction. Does that sound right?
 

mancel

Joined Feb 19, 2017
1
There are several very capable people begging for pertinent information about your project so that they will be able to help you. Take a few minutes to draw a readable schematic with some notes to explain exactly what you need and you will get a solution very quickly. Good lusk.
 
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