Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

Buy Site Supporter Role (remove some ads) | LPF Donations

Links below open in new window

FrozenGate by Avery

Driver board layout Large Images

kiyoukan

kiyoukan

0
Joined
Oct 24, 2009
Messages
2,555
Points
48
So i have been building a driver.
The driver uses 2 3.5V or 3.7V battery's.
Has a v drop of 0.5v at 2A and even less at 1.5A
Also the heat generation at 1.5a is not to bad.
I have prototyped a version of the driver its single sided.
20110904121017.jpg

As you can see it uses no high wattage resistors or parts.
It uses all 805smd components. except for the main chip powerso-10 package.
I am looking for some help.
I can lay out the design but i do not know all the tricky rules like signal trace size or corners and angles and ground planes.
I am looking for someone who is knows there way around pcb layouts.
I want this to be the best it can be.
Also if you know a good place to get the boards made please post that as well.
Chip data.
below
constant current source designed to provide a precise constant current starting from a varying input voltage source. The main target is to replace discrete components solution for driving LEDs in low voltage applications such as 5 V, 12 V or 24 V giving benefits in terms of precision, integration and reliability.

The current is set with external resistor up to 2 A with a ± 10 % precision; a dedicated pin allows implementing PWM dimming. An external capacitor allows setting the slope for the current rise from tens of microseconds to tens of milliseconds allowing reduction of EMI.

An open-drain pin output provides information on load disconnection condition.

* Up to 40 V input voltage
* Less than 0.5 V voltage overhead
* Up to 2 A output current
* PWM dimming pin
* Shutdown pin
* LED disconnection diagnostic
* Slope control with external cap
Best of all no high powered resistors or anything needed. i have one of these in my scanners and im using it as TTL works great.
They say 2A but i keep them at 1.5A
And the slope or slow increase in power to the laser when its first turned on is an amazing feature that will prolong the life more than most other drivers
driver.jpg1

pinconfig.jpg1

driverpackage.jpg1

current board layout.
Chip mounted back side.
omitted reverse protection but would like to have it added back this was for beta testing as the part was not in at the time.
boardlayout.jpg
 
Last edited:





Look into eagle cad, it's easy to learn, and you can find a tutorial for just about anything you need on youtube.
 
that is the one thing im not giving out.
and i have eagle but i know there are rules for laying out pcb traces and i know none of them...
 
kiyoukan said:
that is the one thing im not giving out.
and i have eagle but i know there are rules for laying out pcb traces and i know none of them...
Click to expand...

If you are planing to manufacture these Drives to sell...
then I can see why the secrecy....;)

Jerry
 
I agree use eagle cad, then you can join the rest of us who use dork bot PCB for $5 per square in double sided.

As for traces and what not, I've been told by an associate who used to work for Crown fork lifts designing their PCB's that it's not advisable to use 90deg turns on small traces, because if a fab place uses a rotating bit, it could cut across the trace and you would never notice it.

As for ground planes and what not, if you use eagle cad it makes it easy and could simplify trace layout for ground traces.

Here's some useful links for ANSI trace current limitions, with calculator to help you determine minimum trace widths for a given current->

ANSI PCB Track Width Calculator
The CircuitCalculator.com Blog » PCB Trace Width Calculator
 
well if there is a member here who would call them selves an expert i would love to send a copy of the driver file for a once over before i go and get 100 of them made.
i also plan on placing a large order of battery terminal connectors.
Basically round chips for the positive battery contact.
Also for any one who gives good amount of help a free driver is the least i will offer.
 
You might want to pay special attention to table 4 in your data sheet. If you screw up the on-board heatsinking then you have to add an external heat sink to achieve a 445 diode running at 1.2 Amps.
And on a side note, take off some of the pics or anybody can find your secret IC in less then a minute... :shhh:
 
Thanks. and yes a small heatsink is required. i have solved this problem.
I make my own custom half moon heat sinks.
It slides right in behind your axis housing for perfect thermal contact.
but the heat is not that much also depends on what battery's you use.
if you use 2 3v or 2 3.6v
due to the fact i dont have to pay for most my parts just board and time i want to produce these to replace the current linear drivers.
i tried only once to drive a lm317 at 1.5 and found its a very bad idea. get so hot it burnt me,
These chips even running at 1.5 no heatsinking at on not even mounted on a board when given 6v it took a good 1 to 2 min before it got hot and another min after that before thermal shutdown.
but i just love the soft start feature.
The only other driver i have seen with it is the old die4drivers.
 
Last edited:
yup just trying to find the best place to make the pcbs
any know where jib got his made?
 
Ah well... secrets tempt me too much, but it seems like a nice chip. I guess you should do a better job at keeping things a secret though, it took me about 5 minutes to find the chip at sgs thomson - i should get myself some of these Current Source 2 Amp chips to play with :D
 
You must log in or register to reply here.





Back
Top