Tascam CD-500B Button Repair

The Tascam CD-500B is one of a sadly quickly dying breed — a professional grade CD player, with balanced audio output (and AES/EBU digital) as well as RS-232 and contact closure remote control. Unfortunately, it features some very non-professional grade buttons on the front panel. I don’t even understand what on earth they were thinking.

Symptom: Buttons “fall” into front panel. Operation of button is impossible.

Broken off button
Button with broken hinge. Note that the switch is off center and sort of BESIDE the button, not directly under it as it is on Denon players

Problem: Thin plastic hinge section of button has broken.

Solution: Wedge button in place from below so it’s trapped between the front panel, the wedge, and the switch on the circuit board.

Disassembly of the player: This player is truly and sadly built like total BPC (Black Plastic Crap). You have to remove the rack ears, top cover, and the entire front panel. Carefully release the wires going to the front panel and unscrew the one visible grounding jumper. Unplug the two multi pin connectors (they cannot be mixed up – different number of pins). Remove all the silver screws around the front of the player and release the tabs on the right and left sides, then drop the front forward. Remove two screws holding in the LCD, then you can unscrew and remove either button board as needed.

Wedge the broken button(s) from below, then set them into the front panel with it tilted downwards and reassemble.

It is worth noting this player uses what appears to be a standard slotload SATA cd-rom drive as its transport! I have not tried substituting drives yet to see what happens. The buttons break before the transport 🙂

When you and your Arduino do not give a fuck

I can say fuck on the Internet, right?

the wiring is


// fucks.ino: Arduino sketch for automatically running out of fucks to give. Should work on any board, wired to an HD44780 based display or compatible. Does it look like I give a fuck?
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
// rs, enable, d4, d5, d6, d7
// on the lcd end these match to:
// 4, 6, 11, 12, 13, 14
// don't forget the 10k pot between gnd/5v with the wiper on lcd pin 3, ground pin 1, and +5 on pin 2,
// or a completely negative number of fucks will be given. this is undesirable but hilarious.
int fucks;
void setup()
{
fucks=100; // or whatever. watch me give a fuck.
lcd.begin(20,2);
lcd.setCursor(0,0);
lcd.print("Fucks To Give:");
lcd.setCursor(0,1);
lcd.print(fucks);

}

void loop() {
if (fucks>=1) {
lcd.setCursor(0,1);
lcd.print(fucks);
delay(250);
fucks--;
}
if (fucks=0) {
lcd.setCursor(0,0);
lcd.print(" Out Of Fucks ");
lcd.setCursor(0,1);
lcd.print("To Give! Fuck Off.");
delay(30000); // or just go fuck yourself
}
}

I could put up an example picture and video but I am out of fucks to give

Cleaning your MAF sensor for performance and profit

2012-12-30 19.46.01The MAF sensor is a device that measures the amount of air flowing into your car’s engine air intake and is used to determine the appropriate amount of fuel to shoot in to achieve an optimal fuel/air ratio. Incorrect MAF sensor readings, caused by contamination, can lead to loss of performance, fuel economy, or rough running. That being said, let’s begin! This will take only a few minutes and will most likely save you money on fuel when it’s done.

First, obtain a can of MAF sensor cleaner. Your local auto parts store should have it, and a can is probably good for 5-6 cleanings. Clean it whenever you clean/replace the air filter.

On some vehicles you will have access to the MAF sensor immediately upon opening the air filter housing. On others there will be stuff in the way and you’ll need to remove it from the intake line. It’s usually held in with two screws.

Mazda 6 (2.5 L4) MAF sensor. It's located just beyond the air filter box.
Mazda 6 (2.5 L4) MAF sensor. It’s located just beyond the air filter box.

Step one: Remove the screws holding in the sensor and pull it out CAREFULLY – do not touch or damage any of its parts. Some sensors may have a fine platinum wire that must not be damaged or… well, you’re stuck buying a replacement for something that has a platinum wire in it. Gross. 😀

The pictures shown here are on a Mazda 6 with a 2.5 liter L4 engine; however, I’ve seen the exact same MAF sensor setup on many other import and domestic vehicles including Toyota, Nissan, and *some* Honda vehicles (they only recently started adding MAFs — many Hondas simply do not have one and rely instead on manifold pressure + throttle position to determine the flow rate).

Step two: Spray it down!

The spray can may come with a straw – you can attach that to the nozzle and use that, but do not stick the spray straw into any part of the sensor. Do not touch any small wires on the sensor or expensive problems will result. This sensor appears to simply have none. I’m not totally sure how it works, but the fact is, it doesn’t work well if it’s grungy. 🙂

The cleaner works very quickly but I usually try to spray it, let it stay soaked for a minute, then spray it down again to rinse. Repeat if you still see any visible contamination.

Rub a dub dub, baby.
Rub a dub dub, baby.

Step three: Reinstall the sensor and you’re done!

Now start up the car and drive off, you may notice an improvement immediately. If you don’t, you probably will the next time you fuel up.

A random tip: Track your gas mileage at http://www.fuelly.com and compare it to that reported by others to make sure your vehicle’s running well.

The Water Cooled IC-V8000

I’ve always had a soft spot for the way Icom designs their mobile ham rigs. See, someone at Icom realized that hams are ridiculously longwinded and will overheat many commercial grade radios made for the typical 5/5/90 duty cycle (5% TX, 5% RX, 90% standby) easily… so they designed most of their radios with giant passive heatsinks integral with the exterior chassis of the radio. On some of their radios there is a small cooling fan at the back that pushes a little more airflow over the chassis if needed. I used to have an old IC-229H which just had a huge passive heatsink at the back, and there’s an IC-2100H in my parents’ car that just does the whole case/heatsink thing for cooling.

Unfortunately someone, in the process of building an Echolink node around an IC-V8000, thought they needed a bit more cooling and then this happened…

 I don’t entirely understand WHY this was done — the radio has a very large heatsink of its own… or HAD a very large heatsink of its own, as it may be. It’s a 75W radio and could easily be turned down to mid or low power to further reduce heating problems without doing… that.
The images were found on Facebook and I’m presenting them anonymously to protect the guilty party XD
Shown below is an unmolested reference model:

User interface design FAIL? In MY automobile?

It’s more likely than you think!!

 

The next time you turn on your car, leave the key in the “RUN” position without turning it all the way to start and look at the lights that will appear on the dashboard. You should notice somewhere a small battery icon.

And there, folks, is the fail, for despite being a glowing battery icon, this light does not indicate a problem with the vehicle’s BATTERY.

I’m not going to put up schematics and stuff because that’s just getting too technical* for this. In short, the battery light indicates a problem with your vehicle’s ALTERNATOR.

The ALTERNATOR light, which inexplicably has a freaking BATTERY painted on it, indicates that the vehicle’s alternator is not charging the battery when it SHOULD BE. It came on when you turned the ignition on without starting the engine because the alternator is not being spun by the engine. Once the engine is running it should go out, because the alternator is being spun and is generating electric current to recharge the battery.

You may see the light occasionally flicker under any situation that keeps the alternator from spinning. Driving through a puddle may wet the belt and cause it to slip, causing the light to flicker. Forcing the engine RPM too low on a vehicle with a manual transmission will also make it flicker. In either case it will go out once the alternator spins back up to operating speed.

If the alternator fails to generate power, due to a broken/failed belt (you may also notice a loss of power steering assist and air conditioning!), the light will come on. The car will stop running once the battery runs out of power.

If the alternator itself fails, it may also turn on the battery light. Note that the battery light signal is generated by the alternator, so a particularly rotten failure of the alternator’s internal electronics may not necessarily turn on the light. My father had the electronic voltage regulation controls inside the alternator on a Volvo 740  fail like this while driving on the Florida’s Turnpike in the middle of nowhere – the first sign of trouble was when the antilock brake controller (dimly) illuminated its fault light due to the low input voltage!

Soooo… why not label the light “ALTERNATOR”? Even the execrably designed NABI 40LFW transit bus has the light labelled as “GEN STOP”. Suggesting that it means the GENerator has STOPped working is infinitely more useful.

* me, resisting the urge to geek out about how this actually works? INSANE

Miami and Tampa Frequency Lists for the Wouxun KG-UVD1P

Hey, it’s me, I want to give you some good frequencies…

Miami Area Repeater Listing

Tampa Area Repeater Listing

Use KG-UV Commander to edit and transfer the files to the radio.

Under the hood: Morningstar SunSaver MPPT.

Buckin' Bronco

This is the Morningstar Sunsaver MPPT charge controller, capable of pumping 15 amps into a 12 or 24 volt battery system from an up to 75V input. It’s fairly simple, though the 6P6C jack can be used for Morningstar’s Modbus system or Remote Meter to add more control, programming, and monitoring capabilities. The unit is driven by a Microchip PIC18???* microcontroller.

A typical MPPT controller consists of a switching buck or buck-boost converter with the input connected to the solar panel array, and the output connected to the battery system. A microcontroller monitors the solar array voltage and current (and multiplies them to calculate the power) periodically, and adjusts the switching of the converter appropriately to keep the input side voltage at the solar array’s maximum power point, Vmp.

Inside the Morningstar Sunsaver MPPT, there is… a switching buck converter with a micro… etc. Here you go:

* The conformal coating stuck to the top of the chip made it difficult to read. Like the flavor of PIC matters? XD

Control/Logic Board

No fans or other active cooling are needed. The inductor is thermally coupled to the back of the housing, which is a tall metal fin attached to the heatsink/base. The switching transistors are, undoubtedly, potted somewhere in there. The potted construction is also used on the SunSaver PWM controllers.

Simple, elegant, but here’s the big question: WHY does it cost $250?! Rest assured, I’m scouring the market for some *good* low cost MPPT controllers. This is just a very good and not quite as low cost controller!

The AIMS Power 3000 Watt Inverter/Charger

I’ve been having fun with this AIMS Power PWRIC300012W while pretending to be productive here at the office for the last couple of days.

Franklin from IndoorGenerator sent this unit over for me to play with, and I’ve found it to be very good. The unit combines a 3000 watt modified sine wave power inverter, automatic transfer switch, and 30 amp smart charger all in one nice, compact, lightweight package.

Yesterday I beat the holy splunge out of it with various test loads including a portable air conditioner and large 1/3 horsepower AC motor, and ran it at 2.8KW output for the better part of an hour. It barely even got warm to the touch.

From my testing, I found that the inverter only has two weaknesses to it.

First, like any high frequency switching type inverter, it can sometimes run out of power and turn off suddenly while trying to start loads with a large inrush current. This includes large halogen/incandescent lights, large motors, and compressors. If you’re starting such a beast off a switching inverter, it should be the first thing to be turned on, and any other loads should be removed before attempting to restart the large motor/light.

Charger board - J1 and mysterious green LED near center

Second, the transfer switch isn’t instantaneous. The power goes off for about a second during the transfer from battery to AC or AC to battery.

A very useful little LED meter is present on the end of the unit next to the outlets. By pressing the button next to it you can select whether to view the battery voltage, DC input amperage, or AC output wattage in Kw. While AC power is present and the unit is charging the batteries, the output Kw and DC amperage both show as zero. I would have liked to have a DC current measurement visible during charge like the Xantrex TR series provides, but I’m not gonna complain much about it.

When the inverter goes into overload, the LED display on the end shows “E01″. I also managed to get the inverter to glitch a couple of times – weird things happened like the battery voltage reading coming back as ” 0.4″, or the inverter shut down and showed “Err”. Both of these problems went away as soon as I replaced a 1 AWG battery cable in the test setup which was becoming stinky hot! Oops. Too much voltage drop!

As the inverter begins to get near maximum power output, the peak to peak voltage begins to fall a bit. The unit compensates by shortening the 0-volt pauses on each cycle to maintain 120Vrms through manipulation of the duty cycle. Lights will not change brightness, but some AC induction motors may become weak as the wave approaches being a 120V peak to peak square wave. I noticed this only after applying around 2.7KW of load. The Daewoo portable air conditioner I was running did not show any problems with this, but a large industrial fan (of doom) began to slow down a little.

The charger is rated at 30 amps output. I clocked it at 33-34. It is, interestingly, built on its own board inside the top of the unit. This is a lot different than the charge system in the Xantrex Freedom series units I’m used to refurbishing, on which the same (massive) transformer and transistors are used to convert and regulate the current for charging. The internal 3-stage charger works fine on flooded cell batteries, but the absorption voltage got too high for a gel battery. I measured 14.82VDC. This may be in range for AGM batteries, however — check your battery manufacturer’s recommendations!

Today, I popped the top off and started looking around inside.

The build quality is very nice. It appears that the lower board is in charge of converting 12VDC to 170VDC. The board at upper right contains the AC transfer circuitry, a current sense transformer, and an H-bridge to chop the 170VDC into modified sine wave. The board at upper left is the charger.

The charger board has a jumper (JP1) located on it. Removing JP1 and turning on the charger activates equalize mode (about 15.3VDC). The small green LED located near JP1 comes on when the charger is in absorption or equalize mode. Unfortunately, significant disassembly of the unit is needed to access JP1, and activating any function of the unit while it’s open like this will expose lethal voltages to the user… so let’s just say that until a switch is brought out to the end panel of the unit, this feature is not Ready For Prime Time. AIMS didn’t even know the jumper was there! I only figured this out as I tried toggling the jumper to see if it was there to reduce the voltages for use with gel batteries.

The cooling fans at the end of the unit run whenever the charger is active, and otherwise… very rarely. It barely gets warm at all while in invert. All of the transistors that have any significant amount of current across them are heatsinked to the extruded, finned alumimum chassis. This is a design borrowed from high power car audio amplifiers, which have to put up with being wedged in all sorts of weird ways into hot car trunks with little air circulation.

My final verdict: If you’re looking for a good low-cost, lightweight modified sine wave inverter/charger, this is probably just what you’re looking for. If you’re running any large motor loads, however, be prepared to go over and reset the inverter when they fail to start.

H-bridge and AC transfer board

If the cost and weight aren’t that much of an issue, I’d step up the Xantrex Freedom or Xantrex TR series; they cope with starting large motor loads by just throwing everything they’ve got at it, current limited only by the inductance of the transformer. The motor makes hilarious sounds and the inverter output voltage dips during the ordeal, but it’ll start the motor, whereas a lightweight switchmode inverter like this will just go “Noooo! OVERLOAD! Now you get to come over here and reset me! HA HA!” Plus, the Freedom and TR have a much stronger charger.

Hey guys stop reversing the polarity on your Xantrex Freedom units :P

Pwnt.
Pwnt.

Or, “Now presenting, the all new for 2011 International Rectifier PwndFET Transistors”

I suspect this happens when someone reverses the battery leads on a Xantrex Freedom series inverter. The IRF1010E HEXFETs are blown to bits! On the power board for a 1000 or 1500 watt unit (they both appear to be the exact same board), there are ten on each side.

The symptoms are usually an inverter which goes through the right motions of going into charge and invert, but no output is seen. Sometimes, the unit even makes the right sort of sound as if it were going into charge/invert. Inspection of the FET board will reveal… this.

The other devices on the board appear unaffected. Coming soon: an experiment to see what happens when the IRF1010E’s are replaced! Does this lead to a perfectly working board… or just an object which remains a paperweight? Stay tuned…