Re: QFP128 desoldering / rework question
I would be hesitant to cut the legs... Too easy to cut any tracks that run from the pad under the chip.
Chip Quik is a little expensive but it works and it is a lot cheaper than replacing a damaged PCB or at a minimum repairing some pads and tracks.
I suspect that some of the other low melting point products work also, but the Chip Quik kit [url]https://www.chipquik.com/store/product_info.php?products_id=210001[/url] comes with good flux and a proven product. It is enough to do quite a few chips and good to have on hand.Re: QFP128...
NCSailor
New Member
Last Activity: 08-29-2019, 08:57 AM
Joined: 03-31-2016
Location: NEW BERN, NC
-
Re: Couple IC and switch questions
The AP1534 and the AP1513 do appear to be similar, however, if the mfr used the AP1534 I would replace it with the same thing as it is available. There may be a reason why they chose the more expensive chip!
Mouser's economy shipping is a $1.60 or so more but I think worth it to get the correct replacement. I also find it usually faster than Digikey's first class option.Leave a comment:
-
Re: Semiconductor manufacturers logos
Here is one to add to your collection
Graham...Leave a comment:
-
Re: Has anyone made ?
I would use ChipQuik before I would go to the trouble of making a tool for what sounds like a one time operation.
[url]http://www.chipquik.com/store/product_info.php?products_id=210001[/url]
No affiliation and it is a little expensive but it really works well for the jobs like this one.Re: Has anyone made ?<br /> <br /> ...tion and it isLeave a comment:
-
Re: Semiconductor manufacturers logos
Thanks. This is very useful. It seems I am always trying to reverse engineer something that doesn't work and identifying the IC's etc. goes a long way to figuring it out.
GrahamLeave a comment:
-
Re: Need a simple small low voltage cutoff circuit
The overall low voltage protection might be a good first step but it is not enough to ensure safety.
Each LiPo cell MUST have both the individual low voltage cutout and possibly more important, a smart charger that will not try to charge an individual cell that is below 3V at the normal charge rate; while also ensuring that each individual cell is never charged at higher than 4.2V.
Your system only protects you while all three cells are at the same voltage. This may be OK for new cells but is an unsafe assumption going...Leave a comment:
-
Re: Importance of electrical silicone sealant replacement?
The sealant actually serves a real purpose,although at somewhat higher cost, the same could be achieved other ways.
In the OP's power supply, just imagine if those Mosfets were not secured. They are mounted to two large heatsinks that would be floating. Every Time that power supply is moved or especially if dropped, the heatsinks will stress the Mosfet leads and solder joints.
Sealant is often used on the large electrolytics in power supplies for the same reason. Due to their height, they are usually mounted...Leave a comment:
-
Re: Importance of electrical silicone sealant replacement?
But if you do put it back, it is important that you select the type carefully. Most silicone sealers are acetic acid based (smell of vinegar) and these do have some electrical conductivity when partially cured and can cause shorts. Also the acetic acid formulations are very corrosive and may cause problems down the road.
Best to try to find an alcohol based version. Silicone itself is non conductive and safe to use as long as it is fully cured.Leave a comment:
-
Re: New Members - please post your introductions here
Hi,
Long time lurker, new North Carolina member.
Interests: Sailing, electronics, microprocessors, metal work (micro lathe and CNC mill, general fixing things.
Professional background: Retired engineer with career in automotive Marketing, Operations and IT. Following early retirement, I have been involved in Yacht design and construction in China for over 10 years.
I am here to learn and occasionally may have some ideas that help.
GrahamLeave a comment:
No activity results to display
Leave a comment: