rc battery charger  - Page 1
Forum section: electronics / beginners

author: fitter108
author_rank: Contributor
timestamp: January 26, 2011, 10:26:05 pm
content: I have a victor engineering Hi Iq battery charger for rc batteries. This charger is at least 20 years old and the company went out of business and of coarse no schematics. The dip chips about 10 in number have been sanded and the numbers are not legable but appear to be off the shelf in the day. There was no patent on the product but it is one of the best chargers ever made. The charger will do battery matching with charge and discharge charts. Has a zapper that burns internal resistance out to make the nicads more effiecent and better discharge power dumps. So to my question Is it possible for someone to reverse engineer this with 10 of the 20 Dip chips most of them 14 pin with no numbers on them. The software chip is still ok and can still be bought online thru the rc world. There is someone selling the programable chips pre programmed with the latest software that was available. To my knowledge there is no one that is repairing these the last guy quit 10 years ago in canada. Your thoughts please. Thanks

author: ElektroQuark
author_rank: Unknown
timestamp: January 27, 2011, 08:15:05 am
content: Hi:Some detailed images of the internals would help. May be someone can recognize parts of the schematics and identify some of the ICs.

author: saturation
author_rank: Super Contributor
timestamp: January 27, 2011, 11:03:22 am
content: That's puzzling, if its the best charger ever made and they went out of business?Reverse engineering is a field on its own, and you need a pro to decipher it as chips get denser.20 year old design could be deciphered by design familar EE, with good likelihood of success, butits a lot of work.As edonork said, a photo helps, because the layout can estimate analog from digital logic. Even if the chips have been sanded, if you use a microscope you may still find traces of the etched numbers.The formal process is you have to trace all the components and create a schematic. Label everything you can label and identify. With a DMM, check the output of each pin as the device is functioning and get voltage levels. Label all the voltage levels on each line. Now check the same with a scope and identify the type of signal on each line.From the signals on each pin, you can approximate what type of chip it was: op amp, clock, logic gate etc.,Now which model op amp, clock, logic gate etc., it is, become even more difficult, but at least you aren't in the dark! Luckily, you can substitute a superior chip for an inferior one, so for example, if you find a 741 op amp, anything above it will work, assuming it has the same pin outs.This info generally helps in troubleshooting and repairing a damaged device, but to clone it, you have to I.D. all the components. This becomes more difficult if there are any custom ICs or memory chips with firmware, as then you need to extract the firmware and reverse engineer that too.

author: Jimmy
author_rank: Regular Contributor
timestamp: January 27, 2011, 03:24:56 pm
content: Zilog - Z80This is a good starting pointz80 require at least one maybe more memory chips or Eprom directly connected, An external clock and a standardthree-state driver chip probably a Z80-PIOIt will have some constant current chips for charging and discharging, voltage regulation chips, voltage sence chips, DC Analoge to digital converterPost some detailed photos pleaseThis is OLD technology and it would be cheeper and easyer to redisign a new charger with the same functionality as it if you wanted another one. its a 20year old design using 30 year old technology

author: fitter108
author_rank: Contributor
timestamp: January 27, 2011, 04:00:03 pm
content: The charger is more likely to be 27 years old. There are a few chips under the keyboard and under the 16x2 display. Here are a few pics to look at if you think I am chasing my tail I wont bother anyone with this. If you think its possible to get this figured out Ill create a schematic. Thanks

author: fitter108
author_rank: Contributor
timestamp: January 27, 2011, 04:02:54 pm
content: Another pic

author: fitter108
author_rank: Contributor
timestamp: January 27, 2011, 04:14:42 pm
content: jimmy you are correct the ZILOG Z8 Z0869108PSC Z8 ROMLESS 9407 CHIP IS UNDER THE KEYBOARD

author: Jimmy
author_rank: Regular Contributor
timestamp: January 28, 2011, 10:57:26 am
content: fitter108 can you post some picks of the back of the board and a pick showing where you connect the batteries and temp probe.You should be able to work out all the functions of the ic 's easily. Now you know what ctl system they are using it should be easy to re engineer a batt charger simalar

author: fitter108
author_rank: Contributor
timestamp: January 28, 2011, 12:19:27 pm
content: The connections are as listed here on front view from left to right - those brass tubes coming up from board are banana jacks. The leads have also brass tubes soldered on them and slide inside. Positive voltage on top Neg on bottom. Power then Meter then Motor/Load the Nicad. When charging or discharging a battery there is a lead set that goes to the nicad and also connects to meter for the internal digital volt meter. Or the motor funtion if for motor break-in and amp check so same leads to Motor/load and the other leads to Meter. The Power of coarse is to external power supply 20vdc Max. I have that covered with a pyramid power supply. I will post a pic of front of cover and it will clarify the connections. The temp probes will plug into the Meter connection instead of additional leads for volts. Either charge by voltage drop or temp of pack.

author: fitter108
author_rank: Contributor
timestamp: January 28, 2011, 12:22:44 pm
content: Cover pic which gives you an idea of the functions aswell.

author: fitter108
author_rank: Contributor
timestamp: January 28, 2011, 12:32:53 pm
content: Picture under display

author: fitter108
author_rank: Contributor
timestamp: January 28, 2011, 12:37:53 pm
content: pic under keyboard

author: fitter108
author_rank: Contributor
timestamp: January 28, 2011, 12:47:25 pm
content: Front right view

author: saturation
author_rank: Super Contributor
timestamp: January 28, 2011, 12:59:06 pm
content: Is this charger broken, or are you trying to make a copy of the whole thing?

author: Polossatik
author_rank: Frequent Contributor
timestamp: January 28, 2011, 02:54:47 pm
content: If this stuff still works then I would put a cover on the eeprom ...it's a nice board but what is the actual intend? repair these or copy them?if you want to copy them I think it would make more sense to simply make a new version with the same features....by the way, a little googling comes a long wayhttp://www.rctech.net/forum/8492431-post66.htmland while they look decent chargers , IMHO this looks like one of those "epic" models that are way overrated and have a almost mystic feeling..In photography you have the same with some lenses... and it's almost always just plain silly.Iwould be surprised if it's really that much better than any modern charger like theIcharger series(just to name one)

author: fitter108
author_rank: Contributor
timestamp: January 28, 2011, 04:33:22 pm
content: I have done Internet searches for at least 6 hours the last few days and have not found what you did. I am trying to clone this just for my personal use and for the electronic education. This answers all my questions about the charger. Thanks so muchI am going to create a schematic drawing and put up on the net for the rc world to use. I know that there are newer chargers out but the people who use this unit wouldnt change for nothing, but they may be missing out who knows. again thanks

author: saturation
author_rank: Super Contributor
timestamp: January 28, 2011, 05:32:10 pm
content: I see. As was posted, your additional aide is knowing this is a Z80 CPU, so many of the chips on board are support chips for the CPU. This might I.D. half the chips. If the charger is not working, but the CPU is, then its on the output power side, this is often the first to go in old chargers because the power transistors/Mosfets diodes could fail from use. Good luck!Quote from: fitter108 on January 28, 2011, 04:33:22 pm

author: Polossatik
author_rank: Frequent Contributor
timestamp: January 28, 2011, 06:29:44 pm
content: Quote from: fitter108 on January 28, 2011, 04:33:22 pmglad I could help, have fun and let us know the result of the reverse engineeringQuite curious what makes these so special.

author: fitter108
author_rank: Contributor
timestamp: January 28, 2011, 07:49:17 pm
content: Mine is not broke it works fine . These are just tanks and could be abused without failure. I have started on the drawings of chip placement with numbers just in paint program saved as jpeg. These have been so hard to get repaired even the people who repaired would sand the chip names. I am just trying to help everyone out that has one.