2 layers177.8 × 114.3 mm
Psu
eshazen/scope-clock
It seems I have a bunch of surplus 12V transformers in my office, so probably will use two of those to generate the +8V and -5V with bridge rectifiers.
66 parts
4 layers116.8 × 111.8 mm
It seems I have a bunch of surplus 12V transformers in my office, so probably will use two of those to generate the +8V and -5V with bridge rectifiers.
- Size
- 116.8 × 111.8 mm
- Copper layers
- 4
- Thickness
- 1.6 mm
- Parts
- 60
- Nets
- 102
- Pads
- 374
- Tracks, vias
- 574, 70
- Pours
- 2
- Routed
- Yes
- KiCad
- KiCad 7 (file 20221018)
- Created
- 9 Dec 2022
- Updated
- 28 Feb 2024
Overview
Dac is an open-source printed circuit board by eshazen, from the eshazen/scope-clock repository on GitHub. It is a 4-layer board of 116.8 × 111.8 mm with 60 parts on 102 nets, routed with 574 tracks and 70 vias.
It is built around the 74HCT245, MAX503CAG+ and 74HC4040D, with the 74LS139PC, 74LS161DC and 74LS174DC among its other parts. Its parts include 20 capacitors, 11 ICs, 8 connectors, 7 resistors and 3 diodes. It belongs with the audio and music boards of this library.
Main components
8
74HCT245
DIP-20-40℃~+85℃ 28ns@4.5V 4.5V~5.5V 6mA 6mA 74HCT 8 8uA Bidirectional TTL-compatible CMOS Tri-State DIP-20 Buffers, Drivers, Receivers, Transceivers ROHSWuxi I-core Elec74 Series
MAX503CAG+
SSOP-24-208mil0.5LSB 0℃~+70℃ 1 10 25us Parallel Voltage Buffer SSOP-24-208mil Digital to Analog Converters (DAC) ROHSMaxim Integrated (Analog Devices)Digital To Analog Converters (DACs)
74HC4040D
SOIC-16-40℃~+125℃ 1 14ns 2V~6V 98MHz Asynchronous Divide-by-2 Falling Edge Up Counter SOIC-16 Counters, Dividers ROHSNexperiaCounters, Dividers
74LS139PC
PDIP-1622ns 74LS 8mA Decoder Single Supply PDIP-16 Signal Switches, Multiplexers, DecodersonsemiSignal Switches, Multiplexers, Decoders
74LS161DC
-0℃~+70℃ 14ns 32MHz 4 4.75V~5.25V 74LS 93mW Asynchronous Binary Counter Programmable divide ratio、Reset function、Cascade counter、Synchronous counting Rising Edge Synchronous - Counters, DividersTexas InstrumentsCounters, Dividers
74LS174DC
-0ns 0℃~+70℃ 1 16mA 20ns 30MHz 30ns@5V,15pF 4.75V~5.25V 400uA 6 74LS Series 8mA Asynchronous Push-Pull Reset Rising Edge - Flip Flops ROHSonsemiFlip Flops
DS1306E+
TSSOP-200℃~+70℃ 2V~5.5V Backup power management and battery charging、InsideSRAM/NVRAM、Alarm function SPI TSSOP-20 Real Time Clocks ROHSMaxim Integrated (Analog Devices)Real Time ClocksEN11-VSM1AF20
-- Lack of specifications ROHSTT ElectronicsUncategorised
README
hardware/psu/README.mdPower Supply
Status
2023-02-23 Mostly working. Relay wiring incorrect (see ECOs). Otherwise all outputs verified working, at least with no load.
Rev A ECOs
- C13 should be much bigger, maybe 4700uF
- Bridge footprints are wrong (holes way too small)
- Relay wiring is incorrect
- Can't use the S4 or S6 outputs of the CW multipler, only S5, S7. Maybe add an S3 tap? In any case, fix J14 wiring.
Requirements
- AC power entry, fuse, power switch
- +8V for logic (~1A) regulator on CPU board makes 5V for DAC (Antek 6.3V winding too wimpy)
- -5V for Z axis drive (low current). Should be regulated
- 8-stage CW generator for -1500V
- Jumpers to select output voltage
- Discharge circuit for power-down
- Voltage doubler for +360V with two-stage R-C filter (200 ohm, 100uF or so)
- Switched AC out (2x?) for 12V filament transfomer plus spare
It seems I have a bunch of surplus 12V transformers in my office, so probably will use two of those to generate the +8V and -5V with bridge rectifiers.
ECOs for Rev 1
- Relay wiring wrong. Cut traces to J1 pins 1,3. Wire pin 1 to Relay pin 11 and pin 3 to relay pin 12. (leave gap in cut, ~180VAC)
- Add bleeder on 360V! (ouch!)
Parts
60| Qty | Value | Footprint | References |
|---|---|---|---|
| 16 | 0.1uF | Capacitor_THT:C_Disc_D3.4mm_W2.1mm_P2.50mm | C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C16, C19, C20 |
| 4 | MountingHole | MountingHole:MountingHole_3.2mm_M3 | H1, H2, H3, H4 |
| 3 | 1.2k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R1, R2, R3 |
| 3 | Conn_02x08_Odd_Even | Connector_PinHeader_2.54mm:PinHeader_2x08_P2.54mm_Vertical | J2, J3, J4 |
| 3 | LED | LED_THT:LED_D3.0mm | D1, D2, D3 |
| 2 | 10k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R4, R7 |
| 2 | 1k | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P10.16mm_Horizontal | R5, R6 |
| 2 | 3.3uF 10V | Capacitor_THT:CP_Radial_D5.0mm_P2.50mm | C17, C18 |
| 2 | 33uF | Capacitor_THT:CP_Radial_D5.0mm_P2.00mm | C14, C15 |
| 2 | Conn_01x02 | Connector_PinHeader_2.54mm:PinHeader_1x02_P2.54mm_Vertical | J5, J8 |
| 2 | Conn_01x04 | Connector_PinHeader_2.54mm:PinHeader_1x04_P2.54mm_Vertical | J1, J7 |
| 2 | MAX503 | Package_DIP:DIP-24_W7.62mm | U8, U9 |
| 2 | SW_SPST | Button_Switch_THT:SW_Push_1P2T_Vertical_E-Switch_800UDP8P1A1M6 | SW1, SW2 |
| 1 | 2N3906 | Package_TO_SOT_THT:TO-92 | Q1 |
| 1 | 32.768 kHz | Crystal:Crystal_C26-LF_D2.1mm_L6.5mm_Horizontal | Y1 |
| 1 | 4.9152MHz | Oscillator:Oscillator_DIP-8 | X1 |
| 1 | 74HC4040 | Package_DIP:DIP-16_W7.62mm | U1 |
| 1 | 74HCT245 | Package_DIP:DIP-20_W7.62mm | U4 |
| 1 | 74LS08 | Package_DIP:DIP-14_W7.62mm | U2 |
| 1 | 74LS138 | Package_DIP:DIP-16_W7.62mm | U5 |
| 1 | 74LS139 | Package_DIP:DIP-16_W7.62mm | U10 |
| 1 | 74LS161 | Package_DIP:DIP-16_W7.62mm | U11 |
| 1 | 74LS174 | Package_DIP:DIP-16_W7.62mm | U3 |
| 1 | Battery_Cell | Connector_PinHeader_2.54mm:PinHeader_1x02_P2.54mm_Vertical | BT1 |
| 1 | Conn_01x04 | Connector_PinHeader_2.54mm:PinHeader_1x04_P2.54mm_Horizontal | J6 |
| 1 | DS1306 | Package_DIP:DIP-16_W7.62mm | U6 |
| 1 | EN11-VSM1AF20 | footprints:SWITCH_VSM1AF20_BIT | SW3 |
| 1 | IM6402 | Package_DIP:DIP-40_W15.24mm | U7 |
Questions
How big is the Dac PCB?
It measures 116.8 × 111.8 mm and has 4 copper layers, 1.6 mm thick.
What parts does the Dac use?
60 parts, built around the 74HCT245, MAX503CAG+, 74HC4040D and 74LS139PC. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the Dac KiCad files?
From the eshazen/scope-clock repository on GitHub, at the commit this page was made from: the board is hardware/dac/dac.kicad_pcb and its schematic hardware/anderson_crt/anderson_crt.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Dac design in my own project?
Its repository states no licence, so its author keeps all rights: ask eshazen before reusing the design.
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