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  1. KrisBlueNZ

    Time delay relay or switch?

    Hi mav76 and welcome to the Electronics Point forums :-) OK, let me clarify your requirements. You have a positive DC voltage in the range 5~12V that enters your relay on a "common" contact. Initially and normally, the relay will pass this voltage to a terminal called "1", but it can be...
  2. KrisBlueNZ

    LED Latch Push Button Help

    You won't get very far if you insult Steve. He is the chief contributor to these forums, and very knowledgeable, as you will see if you look at his contributions on other threads. I suspect he has grown frustrated with you because you have ignored his requests to define your requirements...
  3. KrisBlueNZ

    H-Bridge Circuit Design

    Well, you're right, but the usual solution to providing a "floating" supply for the gate drive for the top N-channel MOSFET is even simpler than that. You just connect a capacitor to the top MOSFET's source, and feed the top end of it from the supply voltage via a diode. When the bottom MOSFET...
  4. KrisBlueNZ

    small signal switching diode

    Glass diodes do not usually have any identifying stripes apart from a single stripe that indicates the cathode. The diode in your third picture has a black stripe at one end; this indicates the cathode. This is the usual marking for diodes. I have seen diodes marked yellow-brown-yellow-grey...
  5. KrisBlueNZ

    H-Bridge Circuit Design

    LOL :-) A small inductor would be better, or just a resistor if you want to save space. The point of using a DC-DC converter is not necessarily to step up or down; it's to provide the floating supply (galvanic isolation) in a compact, easy-to-use package. They're not cheap though, and you...
  6. KrisBlueNZ

    Newbie so Hello !!!

    You could try eBay, obviously. LOL :-) I understand. I was assuming you would have more cartridges than players, so it would make sense to have the MP3 player built into the deck rather than the cartridge. Doing it the way I suggested would give better sound quality and make it easier to add...
  7. KrisBlueNZ

    Data amplification?

    Thanks for the links to the data sheets. Unfortunately, both of them are poorly written and lack detail. The RF803E generates a 7-byte packet at 9600 bps using Manchester coding, twice per second. It's not clear whether it transmits continuously, or just when one or more of the input switches...
  8. KrisBlueNZ

    Overheating mSATA-IDE converter

    I've just looked at the SSD data sheet that you linked to. It says that the current consumption, while idle, is only 170 mA. This shouldn't cause significant heating in the regulator on the adapter board. Or is that data sheet for a different SSD? If so, can you link to the data sheet for the...
  9. KrisBlueNZ

    Overheating mSATA-IDE converter

    Yes, 3.28V is fine for the 3.3V rail. The SSD consumes 2W. Is that from its specifications? That would be 0.6A drain on the 3.3V regulator. If the converter is specified as drawing 0.22W that would be specified at the 5V rail voltage so it corresponds to 44 mA for a total regulator load of...
  10. KrisBlueNZ

    Signal isolation - optocoupler

    There are "linear" optocouplers from Infineon (Siemens) and HP. I've had experience with the Infineon IL300. It contains one LED and two phototransistors. One phototransistor is used by the driving circuit to servo the LED current, and the other is used by the receiving circuit. Accuracy is...
  11. KrisBlueNZ

    Sweep Generator and Breadboard Question

    Just a transformer powered from the mains supply. Look at the circuit for a typical linear supply. Mains power feeds a transformer with a secondary winding that provides, say, 15V AC RMS. That feeds to a bridge rectifier, filter capacitor(s), regulator and so on. You just need to provide the...
  12. KrisBlueNZ

    A myth about Generators and backfeeding

    I think it's possible to feed locally generated energy onto the power grid if that's allowed by the utility company. Of course there are many requirements - obviously, your generator must be locked to the utility's phase and frequency, and the equipment needed to couple them together would not...
  13. KrisBlueNZ

    Newbie so Hello !!!

    Just a random thought here... Could you just mount a memory card (e.g. an SD card) in the cartridge with its pins accessible to make contact with a connector in the player, and put all the MP3 playing stuff in the player? You would just put the music tracks on the SD card as MP3 or WAV files.
  14. KrisBlueNZ

    Off - On - Off timed circuit.

    Start by deleting the resistors, and the series diodes too. The diodes are not needed and will just waste voltage. You should connect a diode across each relay coil to suppress the back EMF that is generated when the current flow is interrupted. Connect them with the anode to the negative side...
  15. KrisBlueNZ

    My Guitar pickup toggle switches

    Those switches have six pins arranged as 3x2, and three positions, right? Then they're probably double-pole ON-OFF-ON switches. Look at the one that you've removed to see whether there are any markings stamped into the metal. Often, they will be marked with ON on both sides. Edit: Here's the...
  16. KrisBlueNZ

    Overheating mSATA-IDE converter

    Hi oussama and welcome to the Electronics Point forums :-) Thanks for the thorough problem description. Re the capacitors. They're probably not the problem. The data sheet shows input and output decoupling capacitors on page 6; the input capacitor is 10 uF and the output capacitor is 22 uF. I...
  17. KrisBlueNZ

    H-Bridge Circuit Design

    1. The MOSFET source/drain are reversed. The source should be grounded. 2. I don't see any need for D3 and D4. If you're generating a constant supply voltage, you should use a fixed duty cycle drive signal to the MOSFET. It would probably be simpler to use an isolated DC-DC converter such as...
  18. KrisBlueNZ

    Data amplification?

    The transistor is used for inversion, i.e. it inverts the data. When the signal on pin 4 of the RF803E connector is high, the transistor's collector (which drives the input of the TX434) is low. When RF803E pin 4 is low, the collector is high. So the signal is inverted. The likely reason for...
  19. KrisBlueNZ

    6 CELL LI-ION 22.2V BATTERY LEVEL MONITOR

    You're welcome! It's a pleasure to help someone who has a brain and is not afraid to use it!
  20. KrisBlueNZ

    6 CELL LI-ION 22.2V BATTERY LEVEL MONITOR

    You catch on quick :-) That circuit looks good. The reason I suggested testing with a run-down battery is that you need to set your hysteresis so that it's greater than the change in terminal voltage when the green LED element changes state. When the LED changes from ON to OFF or from OFF to...
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